56. RATS!
At some point when the group is in an urban environment - in a private dining or bedroom at an Inn, in a dark alley, in a city cemetery, or in a sewer system, one or more of the group may notice a single rat in the shadows, possibly under a piece of furniture, or on a pile of trash (depending on the environment) watching them intently.
If characters attempt to attack or scare the rat away, it will give a fearful shriek and disappear into a hole in the wall.
If characters attempt to coax or befriend, or with magic or skills communicate, with the rat, it will approach. If the party has no way to communicate with animals, it will proceed to run in circles and make pantomime like gestures which the characters may attempt to decipher by means of their intellect or skills. If communication is possible, the rat provides a broken, limited response: "Bad coming. Hungry. Angry. Many flee. No hurt flee when bad comes. Family with fear, senseless run."
The rat can repeat or reorganize the message, but doesn't seem to be able to offer greater detail. After a few minutes of either pantomime or communication, the rat cocks it's head to the side, and flees into a hole in the nearest wall, surface, or pile.
Time should pass - hours, days, perhaps weeks. The next time the group is in a chamber alone (private room at an inn, sewer, night time alley), they will hear a scratching sound from one of the walls. Anyone who listens at the wall hears the sound of dozens of tiny scratchings - claws perhaps?
At which point the wall in question will collapse, and a flood of thousands of fear stricken rats will explode into the room, squeaking, squealing, and running and climbing over anything in their path.
The swarm rolls over the PCs with whatever rules are appropriate for the system. While the swarm is not attacking per se, it inflicts minor damage on the PCs as it rushes over them like a living tsunami. Note whether PCs who are able to act attack the swarm, or do their best to weather it.
Three combat rounds later, the squeaking tide has vacated the chamber and headed down as many different passages, alleys or streets as it can. Looking into the collapsed wall reveals what appears to be some kind of altar and several sarcophagi in an ancient, hidden chamber. The entire chamber appears to shimmer with purple and ochre light, and the altar appears slick.
Shortly after, barbed tentacles appear to push through the shimmering air around the altar, two for each PC, and begin attacking and grappling, attempting to pull anyone it has grappled toward the slick stone altar.
The tentacles are difficult to damage, though are weak to applications of bright light and fire. If the group can either destroy all the tentacles, or use magic to consecrate, bind, or seal the altar, or ranged attacks to destroy the altar - the purple glow fades, the stone of the altar melts into a pile of rancid meat, and the tentacles disappear.
The hidden room seems to be a cross between a tomb and a summoning chamber, the sarcophagi holding ancient dessicated humanoid bodies with horrible mutations - jaws and mouths out of place, bony tentacles, horns, and extra limbs. Minor treasure, magic, or weapons may be found, though any such are covered in nauseating and revolting pictographs that limit their appeal or value. Once the PCs have explored the ancient chamber, and all exited it...there will be a rush of air, a pop, and the room will be gone - and all that will remain will be dirt, stone, or a hole into whatever room should be on the other side of the shattered wall (a noblewomen's bedchamber in an inn, a merchant back storeroom, a busy kitchen, etc) which may instigate it's own encounter with it's own ramifications.
If any of the PCs went out of their way to attack the panicked rat swarm, within a couple of days, at a point where the PCs would be asleep, or otherwise would leave large amounts of their possessions somewhere safe...they will return to find that clothes, backpacks, food, armor, and weapons (if applicable) of the group have been gnawed at and ruined by hundreds of tiny teeth. Most any non-magical possession left behind will need to be replaced completely. Magic items of wand-sized or smaller are destroyed if wood, cloth or paper, or gone if of tougher materials. Food, potions, and alchemical agents will be opened and smeared over all the ruined gear. Tiny rat footprints can be found in the mess.
If the the PCs merely resisted or fled from the rat swarm, no such attack will happen. Rather, the next time the party would be surprised by an enemy or blunder into/fail to find a lethal trap or hazard - a lone rat will appear in sight, and squeak loudly from a direction that alerts the party to enemies, or will run over the trap or nudge something into the trap from it's position, triggering the trap, but nimbly avoiding it and scurry past the PCs.
Just before it disappears, it will stand on it's hind legs, and "bow", then disappear into the shadows.
