The Martian meets Dark Matter in Edward Ashton's high concept science fiction thriller, in which Mickey7, an "expendable," refuses to let his replacement clone Mickey8 take his place.

Dying isn't any fun...but at least it's a living.

Mickey7 is an Expendable: a disposable employee on a human expedition sent to colonize the ice world Niflheim. Whenever there's a mission that's too dangerous--even suicidal--the crew turns to Mickey. After one iteration dies, a new body is regenerated with most of his memories intact. After six deaths, Mickey7 understands the terms of his deal...and why it was the only colonial position unfilled when he took it.

On a fairly routine scouting mission, Mickey7 goes missing and is presumed dead. By the time he returns to the colony base, surprisingly helped back by native life, Mickey7's fate has been sealed. There's a new clone, Mickey8, reporting for Expendable duties. The idea of duplicate Expendables is universally loathed, and if caught, they will likely be thrown into the recycler for protein.

Mickey7 must keep his double a secret from the rest of the colony. Meanwhile, life on Niflheim is getting worse. The atmosphere is unsuitable for humans, food is in short supply, and terraforming is going poorly. The native species are growing curious about their new neighbors, and that curiosity has Commander Marshall very afraid. Ultimately, the survival of both lifeforms will come down to Mickey7.

That is, if he can just keep from dying for good.