A man's brain is eaten by a space worm that humanity drove extinct 150 years ago, and its awakening sends a life pulse across the entire galaxy. To escape the strike team coming to burn the parasite out along with its host, he lets the worm rewrite reality and ends up as a small girl named Rubedo, with no memory of why he chose it. Now Task Force 42, the military's most notorious dirty-work unit, offers her one way to stay alive: recover what she forgot, bring more of the worms back, and burn down the World Tree of the space elves who would kill for that power.