Tread Perilously takes another trip aboard Supertrain with the episode called "The Queen And The Improbable Knight."

When travel writer Barney Sweet (Paul Sand) settles in for a trip on Supertrain, he meets Ali (Mary Louise Weller), a perfectly delightful unemployed teacher who is way, way out of his league. But after a night spent dancing in the disco car, Ali vanishes -- replaced by Alison, a woman who claims to have never met Barney. Soon, the Supertrain staff find themselves fielding his frantic claims that trouble is afoot. Will a contingent of representatives from Montenegro joining the train in Denver have something to do with it?

Justin declares his intention to become the Trivial Time Travel while he and Erik go on a journey to discover the truth about Paul Sand. Justin rates the attractiveness of 1970s male television leads. He also rates the best coach characters in cinema. The pair disagree on the intended tone of the episode. Erik feels "seen" when Barney reveals several too true things about writers. His amateur anthropology studies once again invade the discussion. The shocking lack of Latverian accents leads to a discussion of guest stars Kenneth Mars and Micheal V. Gazzo, and John Adams ends up on the hot seat.