A marvelous, thoughtful piece of science fiction. Kevin McCarthy's performance as a dashing middle-aged professor is exceptional, including a gripping (albeit apocryphal) history lecture, an impetuous marriage proposal, and a surge of guilt and heartbreak. A climactic confrontation toward the end of the episode--beautifully directed, in which a ghostly character appears before Walter Jameson and bids him look into her eyes--calls to mind Hamlet's mournful lament to the skull of Yorick: "Now get you to my lady's chamber, and tell her, let her paint an inch thick, to this favor she must come. Make her laugh at that."