Applicants to the Cosmo Academy come from every star system in the galaxy. Tadatos Lane, an orphan esper from Terra, is one of the young hopefuls. A risky mission simulation aboard an actual derelict spacecraft is the final stage of the academy's entrance exam. The applicants leave in groups of ten for the ships, but Tada's crew is shocked to realize that they now number eleven when they arrive on the Esperanza. Things go wrong as the exam goes, and the mood becomes increasingly hostile. The crew suspects sabotage, and Tada appears to be the most likely perpetrator.