In her breathtaking debut—part space odyssey, part sapphic rom-com—Emily Hamilton tells a tale of galaxy-spanning friendship, improbable love, and found family.

So, here’s the thing: Cleo and her friends really, truly didn’t mean to steal this spaceship. They just wanted to know why, twenty years ago, the entire Providence crew vanished without a trace, but then the stupid dark-matter engine started on its own. Now these four twenty-somethings are en route to Proxima Centauri and unable to turn around while being harangued by a hologram that has the face and snide attitude of the ship’s missing captain, Billie.

Cleo has dreamt of being an astronaut all her life, and Earth is a lost cause at this point, so this should be one of those blessings in disguise that people talk about. But as the ship travels deeper into space, the laws of physics start twisting; old mysteries come crawling back to life; and Cleo’s initially combative relationship with Billie turns into something deeper and more desperate than either woman was prepared for.