Thermite

The door was never meant to open from the outside. It stood at the end of the cremation wing, welded shut after the workers heard something breathing behind the steel. Then the thermite charge burned through the lock, white fire crawling down the frame like a holy infection. Behind it waited a corridor packed with ash, broken pressure pipes, and bodies fused into the walls by heat older than memory. The first step through did not lead into another room, but into the place where the factory had been skipping its dead: a furnace district folded between seconds, still running, still hungry, still stamping names into molten bone.