This encounter takes place at a long-abandoned Ancient supermarket. The PCs could be sent there by a merchant to retrieve canned foodstuffs. A village elder may ask them to go there to find and bring back medications from the "farm-oh-see". Or they may just stumble across the ruined market while on the road between adventures.
Once they arrive, the Mutant Lord should describe the market as being in reasonably decent shape, as the walls are still standing and the roof seems intact (except for a few large holes where the sun peeks through). Upon entering, the market is a fairly cavernous space with row upon row upon row of tall metal shelving units. The outer walls are lined with glass-encased freezer and refrigerator units (all long-empty). A row of check-out lines is at the front of the store and PCs who explore will find a few offices and employee break room in the back. The floors are covered in dirt, dust, and cobwebs, and field mice can be seen scurrying in the shadows.
The Mutant Lord is encouraged to peak the PCs interest in digging around the facility, as it appears that looters and marauders haven't picked the market clean. Have the PCs roll randomly for every hour of searching to locate some miscellaneous items such as preserved food, flashlights, lighters, Ancient coinage, an intact shopping cart, small plastic toys, etc. If the PCs were sent to retrieve some MacGufflin for someone, it should be hard to locate (which gives the Mutant Lord enough time to set up the following situation).
After they've searched for a while, a laser shot should barely miss one of the PCs. They'll probably assume they've been ambushed and will go investigate where the shot came from. At one end of the store, high upon one of the shelves they'll find a Laser Pistol Mark 1 mounted in a tripod-like stand (2 shots left). No footprints will be found at the sniper site, and any tracking mutations will come up short of identifying who -- or what -- fired at them. What the PCs don't know is that they HAVE seen the sniper when they first entered: it's the mice scurrying about.
Hyper-intelligent Mice (200) (AL N, MV 60’ (20’), AC 8, HD 1 hit point, #AT 1 (bite/group), DG 1d6, SV L0, ML 7,
mutations: advanced intelligence, quick mind)
The supermarket is infested by a colony of hyper-intelligent mice. These mice appear the same as any common grey or brown fieldmouse, however they all have human-level intelligence. They are able to read and understand Ancient languages, as well as most languages spoken in the
Mutant Future (although they cannot speak themselves). Because of their
quick mind mutation, they have been able to figure out how many common devices and weapons work, and they are capable of tool usage. The mice have been scaring off potential looters to their nesting grounds for generations, and they've gotten quite good at it. Some of the tactics they have used in the past:
* They've gnawed away the support footing on some of the heavier shelves and have run tripwires they can trigger. if someone wanders down on of the trapped aisles, they can cause the shelves to fall upon them.
* They have a collection of letters from various sources (old magazines, sales receipts, Alphabits cereal, etc.) that they use to leave threatening messages to intruders. The PCs may be surprised to see "GET OUT NOW" or "YOU WILL ALL DIE" written in breakfast cereal on the floor.
* One of the mice could sneak into a PC's backpack and pull the pin on a grenade, or perhaps jam their weapon causing it to misfire. Or they may take a small item from one party member and place it in the pouch of another, sowing distrust and discord.
* They could close a freezer door on the PCs, locking them inside.
* Many heavy items are now perched precariously on high shelves which may come raining down upon the heads of the PCs.
* There are several pistols, crossbows, and explosive devices mounted and/or hidden throughout the store. The mice have them positioned where they will do the most damage to intruders. (Keep in mind that they cannot pick up and aim any human-sized weapon. Rather any aimed weapon is carefully mounted in a cradle device and pointed in an obvious direction, say at an entrance or hallway.
Initially the mice are only trying to scare away the PCs. If the PCs stay in the store, the mice's tactics will become more dangerous and injurious. At some point, the PCs may wonder if the place is haunted or if there's an invisible mutant loose in the store. Whether or not they are able to figure out that the mice are causing all of the mischief is left up to the Mutant Lord. The mice will not reveal their true intelligence though, as it makes it easier for them to drive off the superstitious survivors who may wander in.
If by some chance the PCs are able to make contact with the mice (and if they have not injured or killed any of their brethren), the mice may allow them to leave with a few items from the store, but making it clear they are never to return. But if the PCs are taking everything they can carry, or if any of the mice have been attacked and/or killed, the mice will stop at nothing to not only drive the PCs from their home, they will use a variety of hidden ranged weapons to do it.