After being rescued by the Dauntless, Xander debriefs with the Admiral and is ordered to follow the portals to find Tierney and Eve but to prioritize the destruction of any other weapons.
Admiral Lucas has Osborn thrown in lock up until he divulges what he knows about Eve.
Harlan Fried uses a treatment that sacrifices people to keep him in his clone body.
Using Matta's data, the Dauntless tracks the portal to Clayton's World and finds a colony of humans who had left Earth on an Ark Ship 150 years ago. They are welcomed by Jennifer, the Head of the Council of Elders, who is nearly 24 years old. They discover the culture sends anyone who turns 25 through a portal to unknown destinations.
Zazie and Jett try to have a study group but Jett is unable to help Zazie study. She tracks him down and finds him in the professor's office. She and Jett talk it out and he explains that he's working as a janitor to pay for his tuition.
Jax confronts Jennifer about the portal being an execution device and Eve steps in, explaining that she's there to observe the portal. When Jennifer tries to execute the Dauntless crew, the Pandora saves them but informs them that she's already given the Ancients the go-ahead to destroy this galaxy. Xander throws her through the portal and arrests the Council and Eve, leaving the colonists to build a new life for themselves.
En route back to Earth, Jax refuses to talk to Xander, Eve is smug, and the Dauntless receives a distress signal from a Zatarian ship just before it is destroyed by an energy wave. Matta calculates the wave will continue and wipe of the planet Zatar.