Summary: A large manor lies secluded in the jungle. Only after entering and exploring its depths does it become clear that the entire building is alive and looking to digest everyone inside it.
Discovery: The manor stands alone, with no encircling wall, out in the middle of the wilderness. It appears to be well-kept, but there is no sign of any inhabitants. Nothing is out of place, no footprints nearby, etc. Characters should roll Awareness when approaching, and regardless of the roll, tell them they find no sign that anyone has been here recently.
Exploration: Obviously, Chaos corruption is to blame for the house’s state, which means that anyone who succeeds on an Ordinary(+10) Psyniscience test outside the house or a Routine(+20) Psyniscience test inside can tell that the whole place is soaking in Warp energy. The house has a fairly standard layout for a large manor (you can find a suitable floorplan on Google), but a Hard(-20) Awareness test once inside will reveal that there are needle-sharp spikes housed in secret compartments along every outside-facing door and window, clearly ready to shoot out and impale anyone who attempts to escape.
Any character who tries to leave the manor automatically makes an Awareness test to notice these spikes before triggering them. If they fail to notice, or try to get out anyway, the spikes will jut out to try and catch them. The spikes deal 1d10+3 rending damage, and can be avoided with a Challenging(+0) Dodge test just like they were a regular attack. They’re angled slightly inwards, meaning anything caught on them will be unable to continue moving forward without further impaling themselves. Once a character pulls themselves off of the spikes, they recede back into the walls with a slick, slurping noise. A Challenging(+0) Medicae test confirms that the spikes are organic (this test can also be run if, for some reason, the characters decide to investigate the spikes before they’re triggered). The test gets a +20 bonus if it’s made while they’re still extended, though this requires leaving something warm and organic impaled on them. Whatever the unlucky victim is, they will suffer from Blood Loss by the time the examination of the spikes is complete. A corpse will remain warm enough to fool the house into leaving its spikes extended for about an hour after expiration.
Upon entering the entrance room, characters make an Ordinary(+10) Awareness test. If anyone succeeds, they notice a draft in the house despite a closed door (also: If they left the door open, it’s swung shut of its own accord, possibly splitting the party if they intentionally sent some characters in without others, probably fearing that exactly this would happen). There is a large rug in the entrance that stops just a few feet short of the door, and the source of the draft is a shaft angled at about 70 degrees underneath this rug. The shaft isn’t quite wide enough for a medium creature to fit through without squeezing tight, and if someone attempts to squeeze through anyway, the shaft will constrict around them and attempt to shove them out. A Hard(-20) Athletics check is required to muscle past anyway, and if this happens then the house will begin visibly shuddering and will suck in air in whatever space is available around the character before concentrating that air into a jet and attempting to blast the character out. Hanging on in the face of this takes a Punishing(-50) Athletics check. If the character manages to get past this, they can drop into the lungs in the basement and the house will begin breathing normally again. If a character beats this test and decides to remain lodged in the esophagus, the house will go completely berserk, the teeth on windows and doors jutting out randomly, rocking back and forth like a ship (not violently enough to throw anyone off their feet, but items placed on desks may begin rolling, objects on the edges of tables will fall off, etc.), and after a few minutes of this, the house will asphyxiate and die.
Characters outside the house who attempt to climb it or gain entrance through windows will find them unlocked, however the house’s entire exterior is covered in spike traps and it will stab the shit out of anything that attempts to attack it, so long as that something is within a meter. It doesn’t really have an answer for anything that sits down with a heavy bolter and pours gunfire into it from a distance, so if characters figure out what it is before going inside, they won’t have much difficulty killing it, provided they’re willing to take the time and have the ammo to whittle its health down (if they commit to this course of action, let them know that it will consume 1,000+ rounds and at least 10-15 minutes to do so, but otherwise just let it happen rather than rolling out several hundred attacks).
In the house’s attic is the house’s hollow brain, a huge mass of grey neurons coating every wall and visibly firing with bio-electric impulses. It takes a Challenging(+0) Medicae test here to figure out that it’s a brain, assuming the sporadic, vein-like light patterns don’t clue the characters in automatically. Go ahead and let the characters figure it out from sheer deduction if one of the players recognizes what’s going on. It’s better to reward players for being attentive and to make them feel smart for figuring it out than to strictly enforce who does and doesn’t have appropriate Medicae training to be familiar with what a brain looks like. Figuring out that the brain is organic at all requires only a Routine(+20) Medicae test, but this won’t reveal that it’s an organ, just that an organic mass is clinging to the walls of the attic.
Somewhere in the center of the house is its heart. Every entrance to the heart room is protected by the same needle-sharp teeth that guard exits, but these teeth are envenomed. Anyone who takes at least one point of damage from them is poisoned and takes a level of fatigue immediately. Every round afterwards, they must make a Challenging(+0) Toughness check or take another fatigue level. After making the save successfully three times in a row, the poison wears off, however the character will need rest as normal to recover the lost fatigue levels. If someone wishes to treat the poison, they can make a Medicae test in addition to the character’s Toughness test, and if either test succeeds, the poison is slowed (or, if it’s the third success in a row, cured).
In the house’s cellar are the lungs and stomach. The lungs are a room that’s constantly collapsing and re-inflating, and each round spent there a character must make a Challenging(+0) Acrobatics chest or else take 2d10+5 impact damage (use the Acrobatics test as though it were an attack roll to determine hit location). Exiting the lungs isn’t hard. There’s a door, and the house really doesn’t have any incentive not to let people exit its lungs. The door into the lungs, however, is guarded by envenomed teeth just like the heart and the brain, and these teeth will attempt to impale anyone entering the lungs.
The stomach is just a giant vat of acid with various tubes leading there from the upper floors. Throughout the house are trapdoors. Sprinkle them around until about half the rooms have them. Each trap door room permits a Difficult(-10) Awareness test to notice them, in which case it will also be noticed that they’re always round, never square, and not perfectly round either, but slightly oblong. If a trap door is unnoticed, a random character in the room will step on it and must succeed on a Difficult(-10) Dodge test or else be swallowed up by it. Once swallowed, a character can attempt a Hard(-20) Athletics test to prevent themselves from being swallowed down by the slick tube (which is also actively attempting to push them down) and climb back out before they’ve completely disappeared down the gullet, and thus before the trap door can close back up on them. If this fails, they’re sucked in. They can try to stop their descent again with an Arduous(-40) Athletics test at the exit to cling to the top of the tube and avoid falling into the stomach acids below. If this succeeds, they’re stuck at the bottom and must make another Arduous(-40) Athletics test to climb back up, and even then the trap door will have closed on top of them. It will open back up again if they can deal a single point of damage through the house’s 8 points of armour, but otherwise it requires a Hellish(-60) Strength check to force it open. If deposited into the stomach, characters take 1d10+4 Energy damage each round. They can attempt escape by making a Difficult(-10) Athletics test to reach the door, at which point they must dodge a set of regular, non-envenomed teeth to get out the door. If the teeth impale them, pulling themselves off will cause them to tumble back into the stomach acid.
Confrontation: If the characters make any attempt to damage the house and get through its 8 armour to deal at least one point of damage from the inside, the house will release antibodies to try and consume them. The antibodies have a +50 bonus to Awareness tests to locate anything located inside the house and take no penalties at all for attempting to detect creatures on the other side of a wall or who are hiding in or behind any furniture in the house. In fact, attempting to physically enter furniture (like a wardrobe) only gives the antibodies an additional +20 bonus to finding a hiding creature. If one antibody dies, the house will create another after 1d10+5 minutes.
While killing the house three sheer wounds requires either incredible persistence or calling in a lot of heavy firepower, the brain, heart, and lungs are much more vulnerable. If 20 damage is done to the door to the lungs, they will collapse and the house will begin asphyxiating. The house will go completely berserk for about three minutes, the teeth jutting in and out randomly, trap doors opening and closing, the shaft under the rug in the entrance room gasping for air, antibodies attacking every foreign agent wildly and running around at random if there isn’t something to attack right in front of them. After this, with a final spasm, the house will die.
The same berserk will happen if the heart suffers 20 wounds, but instead of dying after three minutes, the house takes a level of fatigue every round, falling unconscious at its threshold, at which point antibodies remain active and the house will reflexively swallow anything that steps on a trap door, but teeth will no longer jut out when attempting to exit or to enter sensitive rooms.
Every wound to the brain will cause the house to completely twitch out as its nervous system is wrecked, which will cause one round of berserk activity as when the house is asphyxiating or bleeding out. A few random teeth and trap doors will go slack after each wound as a result of the stroke. After 20 wounds to the brain, the house is dead and all activity will cease except for existing antibodies. The antibodies will starve to death after about a 1d5 hours without a living house to sustain them, but will continue attempting to kill foreign agents in the meantime (they will be very, very busy in the final hours of their lives as the house’s other defense fail to prevent the ingress of frogs, squirrels, deer, panthers, alligators, etc.).
Rewards: The house is non-sapient and immobile. It can and will develop an affection to anyone who feeds it regularly, even to the point of attempting to spit them out if they enter one of its digestion tubes and allowing them to enter and leave freely, without attempting to impale them on its teeth, at least so long as it’s not hungry. Since it can’t move and it’s in the middle of goddamn nowhere, its utility as such is limited to being a booby-trapped hideout. Additionally, since it’s of only animal intelligence, it will still devour equipment, allies, or prisoners brought in by its friends if any of those end up on the trapdoors or attempt to exit without being in very close proximity to someone the house recognizes as a friend.
The house’s corpse will begin liquefying just a few hours after death and will be nothing but a skeletal frame (similar to the wooden skeleton of a regular, non-organic house before the walls are put in) within a few days, largely due to wildlife coming in to eat the house once it begins to rot and stops shooting spikes at anything that gets close. If the characters for some reason want to build a regular house on the bones of the monstrous one, that’s not all that different from just building a regular house. If they want to burn the clearly tainted bones to ash, they can do that, too.