A cutaway of a buried shelter, one week at a time. Build generators, trays and reclaim units down a growing shaft, put the right people in the right rooms, and keep food, water and power all running green while the surface leans on the hatch. Overclock a room when you need output NOW and gamble on the fire it might start, watch your crew get better at the jobs you give them, send teams up for salvage, answer the radio, and decide who you let in.