Whichever hook you choose, the adventure begins while the characters are traveling through a remote fey wood. If Infernal Machine Rebuild is played in combination with Lost Laboratory of Kwalish, this could be part of the thick band of woods surrounding the pass leading into the Barrier Peaks, known to be infused with the power of the Feywild. The High Forest in the Forgotten Realms campaign setting, the Svalich Woods in Barovia, or Xen’drik in Eberron also make excellent starting points.
Background
A large section of a fey-infused woodland has fallen under the control of a coven of green hags. Using dark gardening techniques, the hags have grafted myconids into the trees of the wood, creating dangerous hybrids and a spreading corruption.
Opposing the hags' evil is a female unicorn named Banrion. After years of skirmishes, the hags have driven Banrion to an isolated pinnacle of rock. This pinnacle stands among the ruins of an ancient city that once housed the Infernal Machine, until Baron Lum the Mad discovered and claimed it for himself. A fallen clock tower still holds some of the machine’s components, which retain enough power to manipulate time.
Who Dwells Here?
In addition to mundane animals, these woods are populated by numerous fey creatures (including dryads, pixies, sprites, and satyrs). These fey have taken sides in the conflict between the unicorn and the hags, with those corrupted by the hags having gained control over the woods.
The Three Mothers
The three Green Hag are intent on capturing the unicorn, Banrion, and corrupting the entirety of the woods. Over time, they have taken on characteristics of certain animals. Mother Stag, their leader, has enormous antlers growing from her head, on which she hangs herb pouches, charms, and dozens of lit candles. Mother Skunk has wide, white streaks in her long black hair. Mother Mole can hardly see, and constantly sniffs the air to find her way about.
Whenever they are encountered, the hags disguise themselves with illusions, making them resemble kindly dryads with their featured animal characteristics.
The trio’s hag eye is carried by a redcap named Olitor, who uses it to spy on their behalf. Olitor is likewise disguised as a small, disheveled satyr.
Hag Coven
Three hags form a coven, which results in heightened power. For higher-level characters, run the hags with their coven benefits to make a hard encounter. For lower-level parties, consider removing the coven’s Shared Spellcasting. This feature is something the hags gain only after capturing Banrion.
If Banrion joins the fight against the hags, consider providing them a few additional allies to help balance things out. Such allies might include an additional redcap alongside Olitor, or a myconid sovereign from the hags' garden.
Banrion the Unicorn
As the guardian of the fey woods, the unicorn Banrion has grown weary in her losing battle against the hags, and remains effectively confined to the rocky plateau that is her lair. She defends her home forcefully, and assumes that any characters approaching her position are the hags' hired sellswords.
The Fey Woods
The characters' journey through the fey woods takes them through the following locations. There is no map for this section of the adventure, so you are free to place these locations anywhere and to use any appropriate forest battle maps for combat.
Dangerous Pathways
As the characters travel deeper into the woods, they find themselves traversing winding pathways that seem to slowly close in from all sides. At the place where the hags' corruption begins to take hold, the plants have become living traps. Read or paraphrase the following to set the scene:
Your path through the woods descends along a ridgeline, with the trees crowding together under a dense canopy above. The ground is littered with fallen nuts. Tree trunks are coated in thick patches of fungus, and a musty smell fills the air. Yet despite the rising gloom, vivid sunbeams still shine between the trees.
Suspect Fey
At the edge of the corrupt woods, a successful DC 12 Wisdom (
Sinister Sunbeams
At some point, the hags attempt to trap the characters—so that they can then facilitate their rescue. To do so, they cause the sunbeams shining through the trees to subtly shift around the characters. A successful DC 14 Intelligence (
Hazards and Hindrances
The sunbeams act as tripwires, which can trigger a number of possible hazards. Choose from the following (or make up your own effects) depending on your preferred style of play.
Treant Beatdown
Any movement causes the characters to automatically cross a sunbeam, which awakens Grandfather Oak. This corrupted treant has several myconids grafted onto its body. Grandfather Oak uses the treant stat block with the following change:
- The treant has the following action option: Pacifying Spores (3/Day). The treant ejects spores at one creature it can see within 5 feet of it. The target must succeed on a DC 17 Constitution saving throw or be
stunned for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
The treant attacks using its Animate Trees action to add even more danger to the fight. After 3 rounds of combat, Mother Stag approaches and pretends to drive the treant away. See “area Offer of Help” below.
Perilous Exploration
As the party continues on through the woods, the characters must succeed on three DC 14 group Dexterity checks to avoid crossing the sunbeams. Each character gains a +2 bonus to their check if a ranger or druid is with the party. A failed check triggers a random effect. Roll a
- Heavy, spiked nuts the size of mace heads fall from the trees, dealing 2 (
1d4 ) bludgeoning damage. - Arboreal fungus releases a cloud of toxic spores in the area. The character must succeed on a DC 12 Constitution saving throw or take 3 (
1d6 ) poison damage. - Arboreal fungus releases a cloud of confusion spores. The character must succeed on a DC 12 Constitution saving throw or have disadvantage on the next ability check they make.
- A torrent of falling spiked nuts and both types of spores assails the character.
Stopping to rest does not forgo the need to make a group check, as the sun moves across the sky and the sunbeams shift around. If the characters move through the woods at night, the moonbeams function in the same way.
After the third group check, Mother Stag arrives to “assist” the characters. See “area Offer of Help” below.
A Friendly Voice
Olitor the redcap (wrapped in the illusion of a diminutive satyr) appears, and warns the characters about the dangers of the sunbeams. He asks them to wait for Mother Stag, who arrives shortly thereafter.
The shifty Olitor tries to engage the characters in conversation, wanting to learn as much about them as possible. Any character who touches Olitor, or who succeeds on a DC 16 Intelligence (
I Call Gorgon Spit!
The hags are not to be trusted, and characters (not to mention players) are often wise to be suspicious even at the best of times. You can adjust the encounters with the dryad-hags according to the players' reactions as you see fit. For example, if the characters are too wary to follow Mother Stag back to the cottage, she can make her appeal immediately and give them the bridle and the crowns in the woods. Or if the characters travel to the cottage and suss out the hags' true nature, the hags might try to threaten the characters into capturing Banrion, or claim that the unicorn is a greater evil—one that might destroy the woods if left unchecked. Especially if the hags' story of Banrion being an evil unicorn seems too unbelievable, the hags can claim that Banrion is a nightmare in fey disguise.
Seeing through the hags' illusions without touching them requires a successful DC 20 Intelligence (
Investigation ) check. But a character who touches one of the hags does not automatically sense that the creature’s form is false. The hags' clothing, their hair, and features such as Mother Stag’s antlers are all real. Only by touching a hag’s skin can a character detect a difference between the illusory form and the real creature beneath it—and the hags attempt to prevent such contact.If the characters attack and destroy the hags, the cottage can contain a crude map indicating the location of the clock tower bridge if the characters are likely to seek out such a mysterious site on their own. Or one of Banrion’s fey servants (a satyr, a knightly sprite mounted on a stirge, and so forth) can be patrolling the area around the hag’s cottage, and will invite the characters to meet Banrion in gratitude for them dealing with the hag threat.
Offer of Help
At some point, Mother Stag arrives on the scene, playing the part of a helpful dryad. Read or paraphrase the following:
You hear the sound of a singing voice approaching, heralding the arrival of an elderly dryad bearing the features of a stag. Enormous antlers grow from her head, on which hang innumerable herb pouches and charms, as well as dozens of lit candles set on the antlers' points.
“I am Mother Stag,” the dryad says. “Please do not think unkindly of our woods.” As she walks toward you, she easily steps through the troublesome sunbeams without fear. “Things here were not always this way, and it troubles me that good travelers should suffer in a place they should instead find tranquil.”
Mother Stag offers to lead the characters to her tree cottage for soothing tea and a brief respite from their weary journey. As long as they journey with her, Mother Stag’s power keeps the nefarious magic of the sunbeams at bay. She also admits that if the characters are willing, she would like to ask them for much-needed help.
Change of Plans
If the characters decide to not accompany Mother Stag to the cottage—or if they attack and kill her before the offer is even made—they can continue through the woods on their own. Call for three more group checks to navigate the sunbeams, after which the characters either come upon the tree cottage or the clock tower bridge, as you determine.
Tree Cottage of the Three Mothers
Mother Stag’s cottage stands an hour’s walk deeper into the woods. While the characters travel with her, they have no trouble with the sunbeams.
Within a clearing, three massive trees have grown together, their trunks entwining overhead. A hollow between them forms the interior of a dwelling, with thick branches acting as its roof. Dense patches of mushrooms grow in garden plots around this unique domicile.
“Our cottage,” Mother Stag says. “Our dryad trees—some of the last in these woods that haven’t yet succumbed to Banrion’s corruption.”
Mother Stag introduces Mother Skunk and Mother Mole, as well as their helper, Olitor (if the characters have not already met him). In their illusory guise as dryads, they offer the characters shelter and delicious food, as well as a healing tea that fully heals any damage or effects from the hazards activated by the sunbeams.
When the characters have partaken of any aid they wish to take, Mother Stag explains that the woods protected by the three mothers have fallen under the influence of an evil unicorn.
“Just as goodly deities assign unicorns to protect sacred places,” Mother Stag explains, “Banrion serves an evil god, who sent her to corrupt these peaceful woods. Since her arrival, the dark-hearted unicorn has hunted goodly fey into near extinction, with the help of evil creatures that now serve her.”
The Dryads' Offer
The three mothers offer to serve as guides, leading the characters safely through the woods to their original destination. But in exchange, they ask for assistance in defeating this evil unicorn. They do not want Banrion killed, however. Instead, if the characters can capture the unicorn, Mother Stag claims that they can undo her corruption—and perhaps even convert her to more goodly ways. (In reality, the hags wish to capture the unicorn and force her to become their servant and mount.)
Bridle of Capturing
To help the characters in this task, the three mothers have corrupted a
Crowns of the Forest
The dryad-hags also lend each character a woven crown of willow branches—an uncommon magic item called a
While wearing a crown, a character automatically fails any Intelligence (
If a crown is closely examined by a character who succeeds on a DC 20 Intelligence (
The Mothers' Guidance
The dryad-hags lead the characters toward the clock tower bridge, but are too frightened of the unicorn to approach any closer. They leave Olitor to guide the characters the rest of the way. The satyr-redcap leads the characters to the edge of the ruins before sneaking off to hide and spy on their progress.
Treasure
The cottage contains brewer’s supplies, cook’s tools, 250 gp, five potions (of your choice), and a
Clock Tower Bridge
As the characters make their way toward Banrion’s lair, they come across the ruins of an old clock tower, which make an unusual and dangerous bridge.
The trees part to reveal the ruins of an ancient city. All that remains are worn flagstones covered in moss and lichen, toppled blocks of weathered stone, and a former tower fallen and now lying stretched across a fifty-foot-wide chasm.
The chasm fully circles an isolated plateau of rock at its center. More ruins rise atop this plateau, including sections of walls held together by the roots of stunted trees. On the near side of the chasm, the base of the fallen tower can be seen, reduced to a broken section of its former ground floor.
Ruins
This city once housed the Infernal Machine before Lum the Mad conquered those who dwelled here and took the machine with him when he departed. A successful DC 12 Intelligence (
Fallen Clock Tower
The collapsed structure crosses the 100-foot-deep chasm and appears extremely unstable. (Banrion can teleport across the chasm, but does so only rarely. Because she can teleport only once per day, she is wary of being stuck on the other side if the hags' servants are nearby.) The foundation of the tower still rests on the forest side of the chasm—and holds the instrument panel that formerly operated the tower’s time mechanism.
The characters can attempt to cross over using the fallen tower as a bridge, or they might discover the controls within the foundation that allow the bridge to be stabilized.
Manual Crossing
A character can attempt to cross the chasm using the exterior of the fallen clock tower as a bridge, or using its interior as a tunnel. Either way, the character must succeed on two DC 14 Dexterity (
On a first failed check, pieces of the tower crumble and fall 100 feet to the bottom of the chasm, but the character is unharmed. On a second failed check, more crumbling rock trips up or batters the character, who takes 4 (
If failed checks cause significant sections of the tower to crumble, you might decide that the DC of the check to climb across increases, or that checks are made with disadvantage.
Using the Controls
Within the foundation of the tower on the near side of the chasm, an instrument panel is built into the wall. Characters who have seen the planar craft in Lost Laboratory of Kwalish recognize the design of the panel, as well as the silver wires that connect it to the rest of the tower structure.
A successful DC 10 Intelligence (
Two empty slots in the panel once housed the components before they fell loose. A successful DC 12 Intelligence (
Forward and Back
The red component allows the time field to be adjusted toward the future. If the check to do so is successful, the tower begins to rapidly age and crumble. If advanced too far, or if any check made to operate the red component is failed by 10 or more, the tower collapses into the valley with a resounding crash.
The blue component allows the time field to be adjusted toward the past. If the check to do so is successful, the tower begins to revert back to its original condition. If this process is stopped before the tower returns to its standing position, it becomes a stable bridge that can be crossed without ability checks.
Adjusting the time field affects only the tower. Other creatures and objects that might happen to be in or on the tower at the time remain unaffected.
Banrion’s Lair
The rocky plateau beyond the chasm holds the crumbled shell of an ancient castle. Banrion the unicorn makes her home here, along with a number of goodly fey who shelter in a network of tiny tunnels within the ruins. Having long been hunted by the hags and their evil servants, these fey—including sprites, pixies, and good boggles and satyrs—are too weak and terrified to help in any fight.
The unicorn Banrion defends her home and its inhabitants with her life. If the characters threaten or attack her here, she fights to the finish, refusing to teleport away. But if the characters have peaceful intent (most likely because they saw through the dryad-hags' ruse, or they simply want to assess Banrion’s nature themselves), they can approach unarmed and announcing themselves. With appropriate roleplaying or a DC 16 Charisma (
Banrion’s Offer
If the characters agree to fight the hags, Banrion joins them. But she asks that before the fight, the characters help escort the fey living in the ruins across the bridge, then manipulate the fallen clock tower back to its standing position. This seals off her plateau defensively, denying it to the hags in case she falls. (If she survives, the unicorn remains able to teleport across the chasm.) In this way, the characters discover the tower’s controls if they have not already.
If asked, Banrion knows only that the clock tower was once part of an ancient city. She describes its controls as “a magical machine of gems and silver,” but has not approached too closely for fear of the magic it radiates. As for who built the city, she cannot say, as it fell to ruin even before her time.
Who’s Who
In D&D canon, Lum the Mad discovered an artifact of unknown origin (reimagined in this adventure as technology from a crashed planar craft) and used it to conquer large territories in Greyhawk’s world of Oerth.
Opposing him was his former general, Leuk-O, who discovered a second artifact—a “relic of a visiting race of space travelers.” This magic suit of powered armor became known as the Mighty Servant of Leuk-O.
Treasure
If the stones and small tunnels beneath the plateau are searched, a successful DC 14 Intelligence (
Aftermath
If Banrion is bridled, she must obey the characters as they deliver her to the dryad-hags. Assuming the characters don’t uncover the hags' deception (or if they don’t care), the unicorn’s fate is a sad one, as the woods fall under the Three Mothers' corruption.
In this event, some time after the characters depart, they are visited by a knightly sprite on a stirge mount, who has hunted the party down to demand a duel by combat. He explains what the characters have really done, and offers to lead the characters back to the woods to right their wrongs if they can be persuaded to.
If the characters defeat the hags, Banrion returns to prominence and drives the rest of the wicked fey out of the woods. Before the characters depart, she asks them to once more use the panel at the clock tower bridge, adjusting time back toward the past. Combined with her own magical influence, this allows the unicorn to separate the myconids from the trees, returning the woods to their former condition.
Components
With the hags defeated, Banrion has no further need for the clock tower panel’s magical power. She insists that the characters take the two components, both as a reward and as items worthy of magical study. (She is also keen to ensure that the panel can never be used again to adjust time, in case doing so causes the hags or their corruption to return).
If the characters research the components or the ancient city, a successful DC 18 Intelligence (
Regardless of whether the characters take the missing components, their activity in the woods is eventually noted by spies of the two agents, Lynx Creatlach and Sir Ursas (introduced in chapter 2). If Olitor survives, the no-longer-disguised redcap is one of those spies, and has quietly worked for Lynx for years even while serving the hags.