The tower's primary purpose was to act as a guard tower and barracks to defend the valley from any non-Slith intruders with a secondary purpose as something akin to an immigration office. However now it acts as the home to a colony of mechanites - electric sentiences that construct bodies out of available machinery. They were once an annoying parasite for the Slith and now they are all that is left.
The Keytower is constructed from a silver steel-like metal that hasn't rusted or tarnished in any way through the ages. There are numerous window openings on each floor that were once covered with glass. The tower itself is over 400 feet tall and has twenty floors, each floor being about 200 by 100 feet.
The insides of the tower are in far worse shape than the exterior would lead one to believe. Furniture has been reduced to little more than the pieces of metal that held it together, features such as counters or doors are gone except for the occasional metal frame. Everywhere there are panels ripped open and wires hanging out. Anything that might be identified as a device of any sort has been stripped and gutted for spare parts by the mechanites. The elevators no longer work so a long trek up the stairs is required to ascend. Aside from batteries and bullets, there is no in-tact technology here that would be of use to anyone without a fully working knowledge of Slith technology.
The basic mechanite looks like a hand-sized insect made of various electronic and mechanical parts. They are essentially parasites and act with insect-like intelligence. There are larger, more advanced mechanites, usually acting as a sort of leader. The process isn't known but one mechanite usually receives all the best stuff and grows to a larger size than the others. These special mechanites are all unique based off of their location and technology available. They have a higher intelligence based off their size - a human sized mechanite is about as smart as a clever dog, for example.
Throughout the tower there is evidence that these mechanites seem to be preparing to move out. Packs of electronics are piled into improvised carts, for example.
Notable EncountersFirst Floor - Reception
The lowest level of mechanites, gatherers, can be found down here looking for any remaining scraps to take upstairs. One special mechanite resides on the first floor, the Monitor. Vaguely humanoid in shape, child-sized and composed of the various communication technologies that were prevalent down here. It has a shattered CRT-like monitor for a head and rattles off unintelligible gibberish through an intercom in its chest. It can direct basic mechanites so that they can take their turns as interrupt actions at any point in the round.
Fifth Floor - Guest/Holding Rooms
One of several floors filled with what seems like a combination of hotel room and prison cell. One room has "djimyoosh" ("danger") in Slith scrawled on the outer door and it seems to be barricaded. Movement can be heard inside. In the room is a special mechanite that is humanoid (Slith)-shaped. Long ago, when the Keytower fell, this room/cell housed a visiting Slith who had the Slith equivalent of cybernetics. The mechanites burrowed into him and instead of taking the pieces stayed there, absorbing some of him as a collective. He is now nothing more than a mad, raging skeleton coated in living metallic insects.
Tenth Floor - Armory
Most of the weapons have been disassembled and the parts taken elsewhere. However a good deal of ammunition was left behind. The special mechanite here is human-sized and is made up of various bullet and energy clips. When damaged it breaks off pieces of itself that explode for medium damage. The basic mechanites in here also carry around explosives and energy packs and act as suicide bombers.
Most of the ammunition is being loaded into carts and being prepared for transport. It looks like another special mechanite made of guns is also being constructed but is currently not moving.
Fifteenth Floor - Offices
The lesser "lords" of the mechanites reside here, the recipients of much of the scavenged tech. Each is about eight feet tall or long, depending on how they choose to present themselves. They consists of masses of random equipment though each one has a set of special features:
Lord Blade - The least mobile, Lord Blade doesn't have any discernible form but rather is an amorphous mass that largely consists of various blades and sharp objects. Lord Blade is less of an attacker and more of a slowly moving dangerous piece of terrain.
Lord Data - Humanoid and consisting of mostly information technology and office supplies. Lord Data has control of all the machines here. He can create zones of falling debris, attacks from loose electrical wiring that suddenly appears and can direct basic mechanites like the the Monitor.
Lord Blaze - Mobile and nimble, Lord Blaze has numerous appendages that end in different ranged weapons that is is continually firing during combat. Basic mechanites are continually feeding him random ammo so each round he may be firing either bullets, lasers, explosive rounds or energy blasts.
There is a map of the valley here. Each of the locations are labeled in Slith:
Power Station - "Pee thih"
Military Base - "feh"
Energy Research Facility - "suh"
Skyfall - "taw"
Biological Research Facility - "shoo..." followed by Slith question marks.
Launch Pad - "huoh / meengh"
Twentieth Floor - The Keeper
The top office gives a magnificent view of the valley. The only resident here is the Keeper, a slim, six foot humanoid that seems to be comprised entirely of wires and plastic cards. The Keeper is non-violent and is capable of computerized speech, simplified since it hasn't fully interpreted whatever language the PCs speak. It is continually switching between personalities - sometimes an analytic scientist, sometimes a military soldier, sometimes a worker drone, sometimes a simple janitor. However the whole time it will talk about having some goal as if these personalities were all working together for something. This goal somehow involves leaving the tower, opening the gate, exploring heaven and finding the gods. The conversation should be disjointed and cryptic. The Keeper will give a final warning that the gods left behind a mess and wishes the PCs luck in cleaning it up themselves. He then collapses into his component parts with a single basic mechanite at the center. The cards are all magnetic ID cards than can be used throughout the valley.