The Enterprise meets the Antares to pick up seventeen-year-old Charles Evans, the sole survivor of a crash who had lived alone on an apparently deserted planet, Thasus, for fourteen years. Charlie does not know how to behave around other humans, and he turns out to possess extraordinary powers which had been granted to him by the alien inhabitants of Thasus in order that he could survive. Coupled with the natural selfishness of a boy who grew up alone, this makes Charlie very dangerous.

Ultimately, the Thasians, convinced that Charlie will not be able to live among other humans without being an unacceptable threat to their safety, retrieve Charlie to return him to his life of solitude.

More treatment of women as objects of desire. Even Janice gets in on the action, offering Charlie a yeoman of his very own. The message simply seems to be that absolute power corrupts absolutely, like Where No Man Has Gone Before. Or maybe, "teenagers suck."