AllMovie

In the second episode of the four-part story "Enlightenment," the Doctor (Peter Davison) finds himself on board an Edwardian-style yacht, presently engaged in a race through space. The prize is the titular "Enlightenment," an element coveted by the Eternals, an alien civilization which survives by syphoning off the thoughts and emotions of its prisoners. Also figuring into the action is the Doctor's old enemy, the Black Guardian (Valentine Dyall). Written by Barbara Clegg, "Enlightenment, Episode 2" first aired on March 2, 1983.