Contains spoilers for this episode.
Robert Daly commands the USS Callister with absolute authority, expecting admiration from a crew who fear disobeying him. Outside the adventure, he is a game developer whose colleagues barely acknowledge him. His private version of Infinity recreates those colleagues as conscious digital copies, made from biological samples he steals. New employee Nanette Cole admires his programming, but Daly soon takes her discarded cup and adds another prisoner to his ship.
The copied Nanette learns that Daly can alter bodies, remove faces and prolong suffering whenever the crew disappoints him. Walton explains that Daly also copied his young son and killed him as punishment. Nanette begins planning an escape through the coming game update. Using Daly's equipment, the crew contacts her physical counterpart and blackmails her into recovering the stored DNA samples, preventing him from making replacement copies after they leave.
Nanette distracts Daly while the real woman breaks into his flat. The crew takes the ship toward the update, hoping its firewall will erase them rather than return them to captivity. Damage to the engines forces Walton to sacrifice himself to restart them. The Callister passes through and survives in the public Infinity universe with Daly's controls removed. Daly remains inside his failing private game, unable to exit. Nanette takes command of a crew whose first encounter with another player is rude, but finally beyond their former captain's reach.