T'Lyn's emotions spread telepathically through the crew after Betazoid diplomats seize the ship.
The Cerritos escorts three Betazoid diplomats while T'Lyn, unhappy in Starfleet, drafts a request to return to the Vulcan ship Sh'vhal. When the crew begins acting erratically, Freeman suspects Zanthi fever, but the Betazoids turn out to be undercover intelligence agents who take over the ship.
T'Lyn realizes that her own conflicted emotions are spreading telepathically through the crew, and she feels she has failed as a Vulcan. Mariner restores her confidence, the crew returns to normal, and T'Lyn decides to stay. Boimler's attempt to train with security is frustrated by their games until he sees them easily overcome the Betazoids. The Betazoids leave behind an image of the mysterious ship.