She proved herself one of the best starfighters in the human enclave of Detritus and she saved her people from extermination at the hands of the Krell - the enigmatic alien species that has been holding them captive for decades. What's more, she travelled light-years from home as a spy to infiltrate the Superiority, where she learned of the galaxy beyond her small, desolate planet home. Now, the Superiority - the governing galactic alliance bent on dominating all human life - has started a galaxy-wide war. And Spensa has seen the weapons they plan to use to end it: the Delvers. Ancient, mysterious alien forces that can wipe out entire planetary systems in an instant.