Fifteen years ago, the Book of Cylinders fell into the hands of the archivists and librarians of Candlekeep as part of a collection of works recovered from a ruined keep in Tethyr, far to the south. It describes a conflict between a settlement of grippli (froglike humanoids distantly related to bullywugs) and an invading force of yuan-ti. The explorers who found the Book of Cylinders and bore it safely to Candlekeep claimed it wasn’t a historical account, but a warning of dire events yet to unfold.
Beginning the Adventure
While the characters are conducting research or relaxing in Candlekeep, a member of the Avowed approaches them with a book and a quest:
A robed dragonborn clears her throat as she approaches you. Cradled in her arms is a green book. “Please forgive the interruption,” she says. “My name is Pelk, and I speak for the Avowed. You’re adventurers, are you not?”
Pelk is a dragonborn commoner of copper dragon ancestry and a member of the Avowed. Her superiors have authorized her to brief the characters on a situation requiring their unique talents:
“Candlekeep has long relied on a community of grippli to the north for fresh seafood. These frogfolk capture and raise giant crabs as livestock in an offshore cluster of pens they have erected just outside their village, then trade the meat and other salvageable parts for items they can use, particularly those made of metal or glass. Candlekeep has long been a steady customer, but over the last several tendays the grippli have become less and less active, and the supply of food has been all but cut off. To make things worse, rumors have arisen about serpent creatures being seen near the Cloakwood and the grippli village.”
Pelk tells the characters that this news came by way of Mitor Jans, a ship captain who makes a living transporting crab meat to Candlekeep. Pelk also reveals that Jans, eager for shipments to resume, has volunteered to take adventurers by sea to a trading post where they can meet with the grippli leader-in-exile, if they decide to undertake the quest to help the frogfolk.
Pelk informs the characters that the Avowed are willing to pay 500 gp to each character once the threat to the grippli village is neutralized.
Opening the Book
If the characters agree to undertake the quest, Pelk hands them the Book of Cylinders and says:
“This book was brought to Candlekeep several years ago. The explorers who found it claimed it was not a historical text, but a warning. My superiors have authorized me to show it to you.”
Pelk allows the characters to inspect the book. It is surprisingly light, and brief examination shows it to be a cunningly contrived container. Its covering is made of supple leather reinforced with thicker strips of hide. Opening the cover reveals three intricately carved, hollow wooden cylinders and a linen bag of dry clay artfully decorated with a drop of water.
The outside of each cylinder is covered with writing and simple images, apparently telling a story in three parts. If the characters can’t figure out what the cylinders have to say, Pelk or another staff member at Candlekeep can give them instructions.
The first step is to remove some of the clay from its bag and mix it with water to form a thick paste, then spread the wet clay in a thin layer on a flat surface. Rolling one of the cylinders across this surface presses the writing into the clay and makes it readable. After repeating the process for each of the cylinders, the characters have the full story and can use that knowledge to determine what they do next.
The impressions in the clay are mostly characters in the Dwarvish script, combined with simple pictographs that tell a tale about the frogfolk and the serpentfolk.
The first cylinder shows and explains how the grippli became skilled at harvesting giant crabs, which are loaded onto seagoing vessels and taken away while the frogfolk celebrate their newly earned wealth.
The second cylinder’s story begins with serpent creatures lurking ominously outside the grippli village. Then the serpentfolk rush forth, capturing or killing any of the frogfolk who try to stand against them. As the village falls into disarray, the giant crabs escape from their cages and head back into the sea.
The third cylinder depicts, and briefly tells about, the aftermath of the serpentfolk’s assault. The village is vacant, most of its buildings flattened. Still standing is the grippli’s temple to their deity, which has been taken over by the snake creatures.
Unbeknownst to the characters at this time, the ancient story told on the cylinders is unfolding now. Evil yuan-ti are tormenting the grippli, and their goal is nothing less than the obliteration of all who stand in their way.
Learning More
After the characters have deciphered the story told on the cylinders, they can learn more about the context of the situation by talking to Pelk or other members of the Avowed. The following information can be learned:
- Before communications with the grippli tapered off, people who returned to Candlekeep from a trip to the grippli trading post reported that a small band of yuan-ti had taken up residence at an old temple site where the grippli village used to be located. These serpentfolk, unlike others of their kind, are friendly toward the grippli, and the frogfolk are helping them excavate the location.
- One of the last people from Candlekeep to depart from the grippli trading post reports that the place has been overrun by frogfolk fleeing their village, which was invaded by a second group of yuan-ti. These monsters are vicious and cruel, the exact opposite of the earlier visitors.
Northward Ho!
It should be apparent to the characters, from whatever information they have gleaned, that the grippli trading post is the first stop on their mission. The trading post is on the coast, due west of the Cloakwood and roughly 90 miles north-northwest of Candlekeep by sea. They can get there either by accepting Mitor Jans’s offer of transportation, or by a longer overland route that takes them east, north, and then westward through the forest.
Sea Voyage
If the characters need further persuasion, Mitor Jans tells them that he and his ship, the Dog Ear, have made the trip from Candlekeep to the trading post and back again more times than he can count. He and his crew know exactly where to sail to avoid undersea hazards and stay on the most efficient route. If the characters are suspicious of Mitor’s motives, a successful DC 10 Wisdom (
In fact, this is the faster of the two routes. The trip takes a day and a half (36 hours), with no encounters en route.
Mitor Jans
Neutral good half-orc
Mitor (use the bandit captain stat block, if necessary) joined Candlekeep as a young acolyte but soon found he was more suited to a life on the sea. His greatest source of pride is the book he has written about fish anatomy, which includes a detailed examination of sahuagin biology. He is willing to transport the party, but neither he nor his crew will join in a fight.
Overland Voyage
If the characters decline the sea voyage, they can consult a map at Candlekeep that shows the safest and fastest overland route, starting with the Way of the Lion, the road that leads inland (east) from Candlekeep. That road intersects with the Coast Way, which runs north along the eastern edge of the Cloakwood. About 50 miles north along the Coast Way is a trail that runs west into the forest and eventually leads to the outskirts of the area grippli village. This route, well over 100 miles in total, takes at least seven days to traverse by foot, and at the end of it the characters will be entering the village before they visit the trading post. Both of those facts might have a marked effect on how the adventure continues (at your discretion). In addition, you might pit the characters against some random encounters along the way, to hint at the error of their ways in turning down the sea voyage.
Helping the Grippli
The grippli of the Cloakwood are distrustful of strangers but forced by circumstances to consider outside help. The warriors of the village and its leader, Pond Mother, are doing all they can to protect the grippli who have taken refuge at the trading post, and they cannot mount a counterattack against the evil yuan-ti, who have already killed several grippli for trying to stand up to them.
Assuming the characters traveled by ship to reach the trading post, the grippli guarding the dock watch them carefully but don’t speak right away. Grippli have difficulty voicing the language of humans, so they speak in Primordial. (Mitor Jans has some fluency in Primordial and offers to be an intermediary if needed.) As long as the characters are nonhostile, the grippli will allow them to disembark.
Mitor Jans and his ship remain at the dock while the characters go ashore. He suggests that they seek an audience with the grippli’s leader, Pond Mother, to learn firsthand about what has happened. (Fortunately for the characters, she’s not hard to find.)
Trading Post
As the coastal mist clears, you get your first good look at the grippli trading post. Ramshackle shelters are clustered around a large permanent building. The low rumble of many voices softly croaking can be heard as your ship pulls up to the dock, where grippli bearing weapons are waiting to meet its passengers.
The central structure of the trading post is a fortified stone and mud-brick edifice, decorated with the preserved carapaces and claws of giant crabs, where commerce is normally conducted. The ground around it, usually clear of construction, now houses a host of makeshift dwellings, and business has slowed to a standstill. The place looks and feels more like a refugee encampment than a trading post.
The primitive shelters are the new homes of grippli who escaped when the evil yuan-ti came through the village in their search for the earlier group of serpentfolk. All these individuals are noncombatants, with no particular knowledge to be gained by communicating with them.
Pond Mother Speaks
The village’s leader, who holds the title of Pond Mother, is an aged grippli warrior (see area the end of the adventure for her stat block stat block). She evacuated the village when most of the other residents did and has set up quarters inside the large building. Assuming the characters are cooperative, the grippli guards take the visitors directly to her. If the party seems trustworthy, she speaks to them. She prefers Primordial (it’s easier on grippli vocal cords) to address outsiders, but she can speak Common if there are no Primordial speakers in the group.
She informs the party that a small band of yuan-ti arrived in the area over a month ago, claiming to be followers of a benevolent deity they called the Scaled Mother. They were friendly, the opposite of other yuan-ti that the grippli had encountered and fought with. These yuan-ti expressed interest in excavating and restoring the previous site of the grippli village, a mile from its present location. Pond Mother saw no reason to refuse them, since their motives were seemingly innocent. But then, two tendays afterward, another group of yuan-ti came on the scene. These yuan-ti attacked the village, killed any frogfolk who tried to resist, and captured the grippli who weren’t able to escape.
She asks the characters for help, telling them that the yuan-ti have been eating their eggs and tormenting the few grippli who remain in the village. Nothing has been heard from the friendly yuan-ti since the larger force of evil ones descended on the village. Pond Mother fears that either they have been disposed of, or they have been imprisoned in the old temple that lies north of the village. In any event, saving the eggs, or as many of them as possible, is the grippli’s main concern.
If the characters demand payment, Pond Mother can offer the modest contents of the trading post’s coffers (200 gp) for clearing out the village and safeguarding the eggs. She points out that the characters are also entitled to keep any items of value that don’t belong to the villagers.
The trading post is about 5 miles south of the grippli village, which is most easily reached by sea. (An overland trip along the marshy coastline is a fool’s route, fraught with obstacles and perils.) Mitor Jans will transport the characters as far as he can, then drop them off just outside the crab maze that borders the community before turning back south.
Crab Maze
Columns of stone with platforms built around them, connected by rickety-looking gangways that touch the sea or disappear beneath the frothing waves, are arrayed before you. In the distance you can see the marshy shore. Dark shapes move under the surface, and flashes of red carapace draw the eye. This is not a safe place.
Getting to the village is the characters' first challenge. Between the characters and the village is a network of cages where the grippli have kept, captured, and bred giant crabs for centuries.
The crab maze is a collection of low-to-the-water walkways, ranging in height from just above the water to being submerged by up to 2 feet. Each main walkway is wide enough for two Medium creatures to walk side by side, while the smaller branching ones are wide enough for only a single person. Interspersed through this web of rickety wood and netting are processing platforms built around the stone columns, each large enough to hold four creatures. Under the water, in open-topped cages made of netting, lurk a great number of giant crabs that haven’t been fed recently. As the characters start to make their way to shore, the water begins to froth as the giant crabs become excited.
Running the Crab Maze
No craft larger than a rowboat can navigate the crab maze because the water is too shallow and already occupied by angry giant crabs. The characters are dropped off outside the maze at a point of your choosing. The water is only 4 or 5 feet deep throughout this area, but wading to shore is impossible since the crabs are everywhere. The characters' goal is to get to the breakwater that separates the maze from the village while avoiding the crabs as much as they can.
As the characters move, they must make a successful DC 20 Dexterity (
The processing platforms, located wherever two walkways join or intersect, are safe havens. The platforms are high enough above the water that the crabs won’t attack creatures atop one.
Passing the Breakwater
After negotiating the maze, the characters come upon a low wall that the grippli have constructed to keep sea creatures away from the village and to protect the lagoon on the other side from rough water when a storm is raging. This breakwater is made of intertwined branches reinforced by tough vines. Hinged on the sides and split in the middle, it can be opened to allow the passage of small boats. In the closed position, as it is now, the breakwater is not designed to prevent entry to the village by anyone who can simply climb up and over it.
If the characters avoided any contact with the giant crabs, or if they have handled those threats with a minimum of commotion, they can easily move over and beyond the breakwater without alerting the yuan-ti in the village. By taking the shortest path to shore, the characters can make landfall just north of the docks.
Several yuan-ti are roaming through the village when the characters arrive, but the serpentfolk are not particularly vigilant. The characters can earn the yuan-ti’s attention by making an undue amount of noise during their approach or giving themselves away with a display of flashy magic. If they do so, a squad of five Yuan-ti Pureblood ambushes them soon after they get out of the water.
The yuan-ti, overconfident to a fault, are likely to fight to the death without trying to summon reinforcements. To give the characters a stiffer challenge, you can have a patrol of
Village
The grippli village is set near the sea in a brackish marsh. Rising from the muck are circular, domed mud-brick buildings that the grippli use for homes and storage facilities. The carapaces and claws of giant crabs feature heavily in the architecture.
If the characters get to shore without causing a conflict with the yuan-ti, they can move freely (if carefully) around the village. (The evil serpentfolk are here for a particular purpose, and as a rule they have no quarrel with anyone who doesn’t directly threaten their plan or try to impede what they’re doing.)
The ground throughout this area is damp and soft at best. Staying dry is difficult to impossible.
The dozen or so Grippli Warrior (see area the end of the adventure for their stat block) remaining in the village are there only to do the yuan-ti’s bidding; they all show signs of abuse from their treatment. Some are in a state of mourning, after being forced to watch the yuan-ti consume their eggs.
Docks
Unlike the materials used for the crab maze, the docks are sturdy planks of wood tightly fastened together and treated to make the structure waterproof.
Only a couple of small boats remain tied up at these piers, the others having been used by the grippli who retreated to the trading post.
The yuan-ti have no interest in the small boats that are moored here—meaning that if they remain undamaged, the characters could use them for transport when they decide to leave this place behind.
Pond Mother’s Home
The religious center of the village, this enormous building made of wood and mud bricks has been turned into a prison where the evil yuan-ti are holding some of the followers of the Scaled Mother. The hemispherical building, 20 feet high and 50 feet in diameter, is by far the largest structure in the community.
The ground level contains a pool of water in the center, directly beneath an opening in the roof of the same size. The marshy ground around the pool serves as an assembly area for group ceremonies. Two staircases on opposite sides of the dome lead up to the second floor, which is divided into four chambers, each about 10 feet square. Three of these rooms currently hold a total of ten wounded Yuan-ti Pureblood with half their hit points remaining. These benevolent, neutral good yuan-ti are being guarded by four evil Yuan-ti Pureblood stationed just outside the cells.
The guards remain at their stations until they hear significant sounds of activity coming from the ground level, or until a character ascends one of the staircases and comes into their view, whereupon they all rush to attack. The prisoners, even if they’re left unattended, won’t leave their cells willingly while combat is going on.
If the characters dispose of the guards and free the prisoners, the benevolent yuan-ti explain what they know of the situation: they are allies of the grippli who have been victimized by the evil yuan-ti that invaded the village recently. They know from their captors that two of their number have been hauled through the marsh northward to the location of a temple in the old village, where they are to be sacrificed to the evil deity Sseth sometime soon.
Brood Pools
Near the outskirts of the village is the grippli nursery. In five places, built up like the sides of a well, stand 3-foot-high mud-brick walls enclosing 20-foot-diameter circular areas. These repositories, filled with clean, fresh water, are where the grippli lay their eggs and nurture offspring as they mature.
This location is under the control of four Yuan-ti Pureblood and two Yuan-ti Malison (Type 1) (any type). They permit a small number of grippli to tend the eggs, which is why the eggs haven’t all died since the arrival of the serpentfolk. This permission could be an act of mercy, or it could just be that the yuan-ti like to eat the eggs: each of the malisons has been consuming at least one egg per day, and always within sight of one or more of the grippli for no reason other than cruelty.
All six yuan-ti are languishing on the ground between the pools and don’t react until at least one of them becomes aware of the characters. If one of the malisons remains alive after 3 rounds of combat, it pours a vial of poison into the water of one pool, which kills all the eggs in it. On each succeeding round, if the characters don’t prevent it, the same creature moves to poison a different pool until it is vanquished or until all the eggs have perished.
Homes and Storage
The simple domes of the grippli’s residences and storage buildings are spread haphazardly around the marsh. Mud-brick with wicker roofs, they’re modest affairs, primitively decorated with giant crab claws. Most are empty and show signs of abandonment.
Most of the village is made up of homes and storage facilities. The community is all but vacant at the present time, so there’s nothing the characters can learn by examining any of the buildings.
Under normal circumstances, groups of bonded grippli live in each home, which consists of a single medium to large room, lit with simple fish oil lamps. Grippli don’t sleep in the water, but in soft hammocks suspended over it. Their personal effects are secured to the walls above the water in netting. Furniture is of simple but well-crafted wood, or adapted driftwood. Some homes have ceramic and glass jars (obtained through barter) and bronze pots and pans (likewise), used on occasions when the grippli want to cook something before eating it.
Storage huts sit on stilts that keep their thatch floors from getting wet and thus protect the materials stored there from deterioration. Wood and other marsh vegetation used in construction are left here to dry out.
Old Village and Temple
Following the river leads the characters northeast through the Cloakwood. The characters should realize that this is the route to the grippli’s old village, which they have heard about from Pond Mother and perhaps also from the yuan-ti captives.
The old village was abandoned when the grippli realized they would fare better being closer to the water. They relocated to where the village now stands. The only structure left in the old village is the temple—now the site of activity once again.
Before the evil yuan-ti arrived, the followers of the Scaled Mother had begun to excavate the temple ruins, hoping to find evidence of their benevolent deity. The work is continuing under the rule of the evil serpentfolk, but it’s slow going. Several grippli have been forced to continue digging the place out, while their masters stay inside the part that has already been opened up. It’s here that preparations are being made for the sacrifice of the yuan-ti’s prisoners.
When the characters approach the temple, they won’t be able to escape the notice of the grippli prisoners. But the frogfolk know enough to remain silent in the face of potential rescue, and they use hand signals to direct the characters toward the courtyard. From there, the characters can approach the upper court (area area T2), where the prisoners are.
The following locations are keyed to the map of the temple.
T1. Courtyard
At the top of a short set of steps lies an open area enclosed by a ten-foot-high outer wall and paved with tightly fitted stone slabs. To either side are truncated ramps that lead down to a lower area, still blocked with earth and rubble that needs to be cleared away. Ahead of you, some fifty feet away, is another short staircase that leads to a ten-foot-high inner wall with a door-sized opening in it that’s covered by a curtain. Coming from beyond the doorway inside the enclosed area, you can hear the groaning and plaintive cries of creatures being mistreated.
The temple’s courtyard can serve as a staging area for the characters, whose presence will not be noticed by the yuan-ti as long as they remain here. Any grippli in the courtyard when the characters arrive will make a hasty but silent retreat to places of safety outside the temple.
T2. Upper Court
The upper court of the temple has been completely cleared of debris. Six pillars support the ten-foot-high ceiling, and the northern half of the enclosed area is bathed in bright light, making it easy for you to see the horrific scene playing out in the far end of the room.
The following events are unfolding as the party enters. Lashed to a makeshift altar are two neutral good yuan-ti, a Yuan-ti Malison (Type 1) named Maaz and a yuan-ti pureblood named Vorsa. They are being tortured by an evil yuan-ti abomination that is presiding over a ritual. An enormous sarcophagus rests behind them, its exterior carved with serpents. Two Yuan-ti Malison (Type 1), a Yuan-ti Malison (Type 1) and a Yuan-ti Malison (Type 3), are positioned on either side of it. Both are evil. One carries a lantern that is the source of the illumination, and the other one is holding up a chime and preparing to strike it. As the characters take in the scene, the abomination is studying the script on the sarcophagus intently, engrossed in what it sees. At a gesture from the abomination, the chime is struck. As it rings out, the seam around the lid of the sarcophagus glows brightly for an instant. Then the sarcophagus comes open partway, and the bound prisoners howl in agony.
Even after the evil yuan-ti notice the characters, their first priority is to complete the ritual, which opens the lid of the sarcophagus and kills the prisoners. With fast action and accurate attacks, the characters can interrupt the ritual and prevent further harm to the victims. The abomination must use two of its turns to finish performing the ritual, which climaxes with one more sounding of the chime as the lid is thrown open. If the abomination takes any damage before completing the ritual, it stops what it’s doing and turns its attention to the interlopers and attacks them, ordering the malisons to join the fight.
Treasure
The objects used by the malisons are a
Assuming the characters interrupted the ritual, the lid of the sarcophagus is only slightly open, and the chime must be struck once more to open the lid fully. Inside the sarcophagus are two items of great significance to the yuan-ti: a suit of
{@item Serpent Scale Armor|CM}
Armor (scale mail), uncommon
This suit of magic armor is made from shimmering scales. While wearing it, you can apply your full Dexterity modifier (instead of a maximum of +2) when determining your Armor Class. In addition, this armor does not impose disadvantage on your Dexterity (
{@item Serpent’s Fang|CM}
Weapon (longsword), rare
This single-edged magic sword is made from the scrimshawed fang of a giant serpent. Its hilt changes shape to adjust to the grasp of any creature that picks it up. The weapon deals an extra
Aftermath
When the abomination and its malison minions fall, the captured yuan-ti are overcome with joy. They tell the characters that they hail from a land to the south called Chult. They were called into service by the deity they know as the Scaled Mother and followed her portents as they traveled north. They began excavating the old temple, with the grippli’s consent, in the expectation of finding relics left behind by the yuan-ti that raided through this area in ages past. They were unable to open the lid of the sarcophagus once they unearthed it and were in the process of clearing rubble from the courtyard stairs when the evil yuan-ti descended on the village and captured all the followers of the Scaled Mother.
With the threat to the area neutralized, it doesn’t take long for things to return to normal. When the grippli prisoners realize that the characters have persevered, they waste no time getting the news to the village and the trading post. The refugees return home, and within a tenday the frogfolk have repaired any damage to the crab pens and are back in business.
The benevolent yuan-ti, once they recover from their wounds, might decide to continue digging out the temple or to return to their homeland, as you see fit. If the excavation goes on, you can populate the lower level of the temple with treasures or traps at your discretion.
If the characters journeyed by land and went directly to the temple after spending little or no time in the village, the now-freed grippli prisoners explain that other evil yuan-ti are stationed in the village, and they too need to be dispensed with before the grippli can reclaim their homes.
Grateful Grippli
Having done what they came to do, the characters are free to take their leave of the grippli anytime; once regular traffic resumes between the trading post and Candlekeep, the heroes have no trouble finding a ship that will carry them back to the library.
In the meantime, if the characters prevented one or more eggs in the brood pools from being killed, the returning grippli are so ecstatic that Pond Mother offers to perform a ceremony for the party’s benefit, called the ritual of friend marking. If they agree, they are brought to the pool in the center of Pond Mother’s home at midnight. The grippli, croaking sonorously, surround the characters while they stand in the warm water and Pond Mother pours the contents of a jar into the pool. The liquid swirls, and motes of light begin rising up around the characters. Any party members who have second thoughts at this point can avoid the effect by succeeding on a DC 15 Wisdom saving throw. Party members who don’t resist, or who fail their saves, fall into a trance until dawn—when they come to their senses, completely rested and healed. All party members who completed the ritual can speak and understand the Grippli language from now on.
Grippli
At first glance or from a distance, a grippli looks like a large frog. Its head and body are indeed those of a frog, but its front extremities end in hands with fingers that enable it to manipulate weapons and other objects, and its rear legs have similar digits that it can use for grasping and climbing. A grippli can move as quickly on all fours as it can on two legs.
Communal Effort
Grippli rely on ambushes and guerrilla warfare to defend themselves and their settlements. They can snare foes with their tongues to make them easier targets. Grippli villages are generally built from mud bricks and other natural materials harvested from the immediate vicinity.
Young grippli are raised by the community rather than by a single set of parents, and all of a community’s eggs are kept in freshwater pools until they mature. Protecting their eggs is a major concern for grippli, since lizardfolk, yuan-ti, and other creatures are known to have a taste for them.
Close to Nature
Most grippli care more about survival than they do about abstract ideals such as good and evil. Grippli religion is based in animism and nature spirits; the frogfolk do not pay reverence to a single deity, but they might beseech a particular nature spirit for aid from time to time.