At Rigel VII, radiation that erases memory leaves the away team trapped under a tyrant while Ortegas must pilot the amnesiac Enterprise to safety.
The Enterprise returns to Rigel VII, where radiation from nearby asteroids erases memory. Pike, La'An and M'Benga find that Zac Nguyen, an officer believed dead, rules over a caste society in which laborers forget everything each night while he and his guards are shielded.
The away team loses its memories too, but Pike storms Nguyen's castle and defeats him. In orbit, the radiation wipes the crew's memories, leaving Ortegas, who is unaffected, to fly the ship clear of the asteroids. The team's memories return. The episode revisits the planet first seen in The Cage, and Pike also patches up his strained relationship with Batel.