After uncovering a dark Martian secret in their previous adventure, Molly Lennox, Pirra Lennox, and Vicky Valentine whisk off to the outer solar system for rest, relaxation, and to visit a new wonder for a school project: a beautiful alien nebula. It's the last remnant of the aliens that attacked Mars and a tether to her guilt about the death of a friend. It's Molly's wish to see it destroyed and the blackhole bomb will do it.
She just has one problem: her alien sister, Pirra. Molly can't destroy something her sister cherishes. Conflicts roil her, a betrayal by a friend churns wrath within her, and when a mystery object floating within the nebula piques her curiosity. Just when she can't take it anymore, the action starts and she finds herself trapped in space without anything to breath.