For 10 Years, The Army Bombed The Aliens Underground. They Were Keeping Something Asleep

For eight years, a sapper sergeant has walked down into fresh bomb craters at first light and signed them closed. On the siege world of Bracken, six-ton spikes dropped from orbit cave in the tunnels of a burrowing enemy, and his signature certifies the ground has fallen. Every crater he signs is a piece of the war that is over.

Then a crater he sealed in the spring opens again. The thousand tons of stone he dropped into its tunnel are gone. The bone-hard door behind it should be cold. It is warm, and it gives...