Subterranean Frost

Calvin Miller keeps the Blackfoot Agricultural Repository cold. Deep under a Montana ridge, he works the graveyard shift on industrial refrigeration that guards the nation's seed banks. During a routine glycol pressure drop, he finds an unmapped sub-level: three locked chambers converted into living quarters for people who are not supposed to exist. Director Sarah Vance calls it a classified continuity study and forbids him from reporting it. Then Elena, one of the hidden residents, slides a maintenance manifest under his workshop door. Identical cells sit in four other federal vaults. The next supply drop is not freight. It is the last time the blast doors will open. Private security chief Marcus Kane is already sealing the corridors. Calvin has one ugly option: trigger a controlled thermal runaway on the ammonia-glycol grid and force an evacuation before the mountain becomes a tomb. To get the captives into the snow, he will have to survive Kane's sweepers in frozen catwalks and air shafts, and decide how much of the world he is willing to freeze to tell the truth.