Introduction

I was inspired by the 5-Room Dungeon design philosophy when I saw the greenhouse battlemap and immediately divided it into five different sections – one in each corner and then the fountain at the centre. Compared to your typical dark, dank and dusty dungeon, this is just one big room with several explorable areas. Simple to run for a small group who are looking for a light dungeon-crawl one-shot.

Using This Location

The Verdant Cradle works as a standalone one-shot built around the Greenhouse battlemap. It needs no fixed home in any particular world. Drop it wherever a greenhouse would believably stand and let the setting do the rest:

• A public park. Locals stopped visiting after the gates were chained shut. Children still dare each other to look through the glass.
• A private estate. The new owners haven’t worked up the nerve to go inside. The staff have stopped trying to make them.
• A zoo’s botanical wing. Officially closed for renovation. Unofficially, something keeps eating the maintenance schedule.
• A historic botanic garden. A heritage listing means nobody’s allowed to touch it. Nobody’s checked why that suits everyone just fine.

Adventure Background

For thirty years, Yselde Marrow filled this greenhouse one specimen at a time. She traded with sailors, bribed customs officers, and once crossed three borders with a seed sewn into her coat lining. Three expeditions. Two lawsuits. One border crossing that nearly cost her everything. It would all be worth it to see her mother again. 

Yselde Marrow’s mother used to tell stories of fey creatures whose presence made things grow, whole forests thriving in impossible climates, gardens persisting through winter, life persisting through ruin. When her mother died, Yselde stopped grieving and started searching for such a creature. She crossed three continents following the stories until she found Vethraal deep in a jungle that had no business being as alive as it was.

She caught her, used Basilisk’s Tears to petrify her and set the stone into the basin of what is now the fountain. Then she built the Verdant Cradle around her and told herself it was research.

The greenhouse thrived. Everything she planted flourished. Vethraal’s magical presence worked even in her petrified state, a fey creature whose aura alone makes surrounding flora grow in any environment, any climate, any condition. Yselde wrote it up as a breakthrough and never quite finished the paper, because finishing it would have required writing down what she had done to make it possible.

She died at the fountain, trying to bargain with Vethraal to give her mother a second life, but the fey’s influence on the greenhouse had made allies from the flora. 

What the party doesn’t know is that scattered across the Verdant Cradle are the four components of a cure for petrification. Yselde assembled them as a bargaining chip for when she planned to ask to have her mother resurrected, each one chosen with the precision of someone who understood exactly what they had done. 

Important NPCs

Yselde Marrow

Role: The Verdant Cradle’s creator, curator, and cautionary tale. 

Appearance: Small, sharp-eyed, permanently ink-stained at the fingers. She dressed for function: worn field boots, a botanist’s apron with too many pockets, and hair pinned back in a way that suggested she’d done it without looking. She looked like someone who had been in a hurry for thirty years and had learned to be efficient about it.

Personality: Brilliant in a way that makes other brilliant people uncomfortable. She asked questions nobody else thought to ask, reached conclusions nobody else was willing to reach, and moved faster than institutions could keep up with. Academia didn’t reject her; it simply couldn’t hold her, and she told herself that was the same thing. What looked like obsession from the outside felt, to Yselde, like the only logical response to a world that kept refusing to take her seriously.

Motivation: Bring her mother back from death.

Vethraal

Role: Prisoner. The Verdant Cradle’s true heart. 

Appearance in captivity: A figure of extraordinary stillness at the centre of the fountain basin, petrified in the moment Yselde caught her. At first glance, she seems like an extraordinary sculpture. The detail is too fine for chisel work: elongated limbs that taper into root-like fingers, a face that is almost human until it isn’t, appendages along the shoulders and spine that might be wings, or branches. Vines and blooms are worked into her form so naturally that it is impossible to say where the fey ends and the flora begins.

The wrongness arrives slowly. The proportions are not human. The expression is too knowing for stone. And the flowers woven through her, they are not stone. They are fresh.

Motivation: To wake up and expand overgrowth into her captor’s city.

Greenhouse

General Features

Light. Due to the frosted glass of the greenhouse, sunlight gently floods the room in bright light during the day while moonlight only casts dim light into the interior. 

Sound. Though the air is thick, the plants inside the greenhouse shift and move as if a gentle breeze occasionally sweeps through foliage.

The Fountain

Characters who move toward the fountain before exploring see it clearly from the entrance:

A wide stone basin, four smaller basins set into the rim at equal intervals, each carved with a shallow hollow, each empty. At the centre, a feminine figure with elongated limbs and root-like fingers, a face that is almost human, and appendages along the shoulders and spine that might be wings, or branches. At the statue’s feet, face down in the water, is a woman’s body.

The Body. The corpse belongs to Yselde, who was killed by the flora of the greenhouse. In her attempt to bargain with Vethraal, she only angered the plants, causing them to lash out. 

At the bottom of the fountain, beside Yselde’s body, is a second journal — waterlogged with three entries still legible.

Water Whip.  The fountain will not open by force. Characters who reach into the water without must make a DC 13 Dexterity saving throw as a pseudopod of water lashes whips at them, dealing 2d8 bludgeoning damage on a failure or half as much on a success. Those who persist in entering the water draw the ire of a Water Weird that fights until destroyed, at which point it collapses back into the basin without a sound.

South East: The Maw of Kethrani

Vines have reached the windows. Roots have cracked the path in three places. Against the far wall, half-swallowed by its own leaves, sits a pitcher plant the size of a barrel, deep violet and faintly glistening.

The Maw of Kethrani. In its native jungle, it lured insects with a scent like rot and dissolved them slowly over weeks. Yselde fed it scraps from the kitchen to keep it docile. Nobody has fed it in two years. Creatures who approach must succeed on a DC 13 Dexterity saving throw or be grappled by a lashing tendril (escape DC 14 Strength). A grappled creature takes 1d4 Acid damage every minute.

The Vine Blights. Two Vine Blights have taken root in the beds flanking the Maw, indistinguishable from the surrounding overgrowth until they move. They fight to the death. 

Torn pieces of parchment spread between the blights. If pieced back together, a character can read it as two entries from a botanist journal. 

“The Kethrani is not cruel. It is simply honest about what it needs. I find that easier to respect than most people I’ve worked with.”

“I’ll make the cure and show her I can reverse what I’ve done. Then she’ll have to be open to a bargain. Acid from the Maw. Veins of the Ghost. Seasoned obsidian. And as for the blood. I’ll use mine, drawn by the Thornkin. She can’t refuse me after that.”

The rest of the entry features sketches of the barrel-sized pitcher plant in this section of the greenhouse. The author calls it The Maw and was intending to collect the acid from it as a reagent for a potion to cure petrification.

North West: Hollow Orchids

Deeper in, the greenhouse opens into dense layered planting. Four distinct beds, each thriving in a way that has nothing to do with sunlight or season. Clusters of pale, ghost-white flowers grow low across two of the beds. The air here is suddenly cold.

Hollow Orchids. In the wild, they release numbing spores when they feel the warmth of a creature getting too close. Characters who examine the orchids must succeed on a DC 12 Constitution saving throw or suffer disadvantage on attack rolls and ability checks until the end of their next turn.

Lost Spirit. A Will-o’-Wisp drifts silently through the orchid beds, it attacks when characters enter the beds, using the spore clouds for cover.

Veins of a Ghost. Left behind in a root bed beneath the densest cluster is a pressed botanical sample of Hollow Orchids–its roots have dried into a crimson color. A character who succeeds on a DC 15 Intelligence (Arcana or Nature) check knows that this is a common reagent for a cure to petrification. 

North East: Yselde’s Desk

Tucked into the far corner is a small potting desk. Tools laid out. A half-finished pot of soil. A journal, open to an entry that ends mid-sentence. The desk drawer is locked.

Journal. The journal belongs to Yselde and shares her journey (Refer to Adventure Background) as she spirals into the desperation she nurtured as she grieved for her mother’s death. A character reading this understands that Vethraal is a petrified fey creature that is, in fact, being used as a fountain statue inside this very greenhouse. 

Locked Drawer. DC 15 Thieves’ Tools to pick, or DC 17 Strength to force. The key is among the Thornkin Vines. Inside: a small carved obsidian vial containing emerald dust (100gp). Characters trying to brew a cure for petrification know that this obsidian has been seasoned with the emerald dust.

South West: The Thornkin Vine

Threading through the dirt, thickening as it nears the fountain, runs a rust-colored vine with thorns shaped like tiny barbed seeds. Look closely: the thorns pulse. Faintly. Like a heartbeat.

Thornkin Vine. It came from the same expedition that found Vethraal. A character who succeeds on a DC 14 Wisdom (Perception) check follows a vine to where it meets the fountain’s base and a root ball has grown around the brass key to Yselde’s drawer, which the vine reclaimed when she died and has held ever since. The vine does not resist being opened. 

The Needle Blights. Three Needle Blights nest in thicker foliage where the vine is bundled beneath larger plants, indistinguishable from the surrounding foliage until they attack. They target any character who approaches. A DC 18 Perception check spots them before they act; failure means they get a surprise round.

Opening the Fountain

The acid from the Maw of Kethrani, the crimson veins of the Hollow Orchid, and the seasoned obsidian placed into their corresponding basins each respond: a faint warmth, the water in that quadrant stilling, the figure at the centre shifting almost imperceptibly. The fourth basin requires blood. Yselde intended it to be her own, drawn by the Thornkin. The vine doesn’t know the difference. One of the party must choose to press their palm against the thorns and let it fall into the final basin under the greenhouse glass. 

When all four are filled, the fountain opens:

The stone cracks. Not breaking, not crumbling, but releasing. It splits along lines that were never seams, falling away from her in pieces that dissolve before they hit the water. What stands in the basin is no longer a statue. She is tall, impossibly still, and the flowers woven through her are blooming.

Vethraal (Sea Hag Statblock) is awake. She has had two years to think about what she wants, but could the party change her mind?

Conclusion

With Vethraal awakened, the fountain fully drains and reveals a staircase descending into darkness. Here are some ideas of where you can make the adventure continue:

•       A vault. Yselde’s true collection: the acquisitions she never recorded, the specimens she couldn’t let anyone else have. Whatever she valued most, she valued enough to bury beneath the creature she imprisoned to protect it. I’d recommend The Secret Research Facility battlemaps to inspire you on what a botanist’s vault may look like. 

•       A dungeon. The fountain was a lid. Stairs descend into something Yselde never lived to map, built long before she planted the first seed above it. Perhaps the unrest of Vethraal has corrupted what truly lies beneath the greenhouse? In which case I’d recommend The Living Depths dungeon map to expand this short adventure into a mega dungeon. 

Visit our Plants section in the free token editor for a variety of creatures to bring your own greenhouse encounters to life.

Support the Creators

Ian Arguilles
What do Ian, a hydra, and a hat rack have in common? They all wear many hats. Ian freelances across copywriting, short fiction, and RPG design. If you’d rather just hear him ramble about telling better stories at the table, look for Unfound Fables on Instagram.

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