A Locus Award Finalist for Best Novella

Fix the past. Save the present. Stop the future. Master of science fiction Alastair Reynolds unfolds a time-traveling climate fiction adventure in Permafrost.

2080: At a remote site on the edge of the Arctic Circle, a group of scientists, engineers, and physicians gather to gamble humanity’s future on one last-ditch experiment. Their goal: to make a tiny alteration to the past, averting a global catastrophe while at the same time leaving recorded history intact. To make the experiment work, they just need one last recruit: an ageing schoolteacher whose late mother was the foremost expert on the mathematics of paradox.

2028: A young woman goes into surgery for routine brain surgery. In the days following her operation, she begins to hear another voice in her head...an unwanted presence which seems to have a will, and a purpose, all of its own - one that will disrupt her life entirely. The only choice left to her is a simple one.

Does she resist...or become a collaborator?