What the Ice Keeps

Vigil Station has one rule nobody has ever explained: on the first full day of the four-month dark, whoever's cooking leaves a plate of food out past the flags, on a low pile of stones the crew calls the cairn. Nobody remembers starting it. Nobody's ever needed to. Dr. Naomi Kestrel didn't come to Antarctica for the tradition. She came because a season with no way to leave was exactly what she needed after the season that broke her — and because a nine-person winter-over crew is small enough that nobody has time to ask what she's running from. Then the station's drilling program breaks through two kilometers of ice, weeks ahead of schedule, into a sealed stone chamber that has no business being there — a ring of worked cairns, bones carved with a tally kept longer than anyone can explain, and a cold that runs deeper than the bedrock around it has any right to. The dating doesn't make sense. The dig log doesn't make sense. And the harmless little ritual the crew has performed, unbroken, for as long as the station's records go back, starts looking a lot less like tradition and a lot more like a debt somebody forgot they were still paying. As the ice groans toward a catastrophe the instruments say is coming right on schedule, and pale, patterned marks start climbing the skin of everyone who spends too long in that chamber, Naomi has to work out how much of what's happening at Vigil is a documented, deadly, entirely explicable polar hazard — and how much of it isn't. Trust doesn't break at Vigil Station. It erodes, one locked door and one hidden arm at a time, until the only people left to decide what the ice is owed are nine scientists a hundred miles from the nearest living soul, four months from the first plane out, and completely out of daylight. Something has been keeping the ice fed for a very long time. This is the winter the bill comes due.