A small ship, the Antares, transfers a passenger to Enterprise. He is Charles Evans, recently recovered from the lifeless planet Thasus, having survived there since he was marooned by the crash that killed his parents. Oddness seems to accompany Charlie. Antares calls, with a warning her captain does not finish delivering before his ship explodes. Soon enough it becomes clear that Charlie is a young man of extraordinary powers, able to cause things to happen merely by willing them to. Kirk must regain control of his ship from a troubled, dangerously powerful teenager.