Enterprise investigates a stellar nursery with several ships inside. Hailing one, they encounter a group on a pilgrimage to the Great Plume of Agosoria. Every eleven years, one of the protostars emits a neutron blast that the pilgrims consider a sacred event. Captain Archer invites the pilgrims to visit Enterprise. In Engineering, Commander Tucker explains the Warp 5 engine to the pilgrims. One alien disconnects an antimatter junction, and his arm morphs, revealing him as Suliban.
As Enterprise tries to go around a plasma storm, a bolt strikes the ship and causes an antimatter cascade that almost reaches the reactor, but is stopped by the disconnected junction. Tucker detects the sabotage in the junction, but does not suspect any of the crew. Crewman Daniels informs Archer that he believes one of the pilgrims is Silik, whom Archer encountered in episode "Broken Bow". In his quarters, Daniels tells Archer he is not Starfleet but from the 31st century, commenting that the people who command Silik in the Temporal Cold War are from an earlier century. He comments that he has been sent to capture him, and asks for permission to tie his tracking technology into the Enterprise 's internal sensors.
Silik appears to Archer in his quarters and claims that Daniels' group was responsible for the antimatter cascade, and that The Temporal Accord is a lie. In Engineering, Daniels detects Suliban bio-signs, but is surprised and shot by Silik. T'Pol and Tucker summon Doctor Phlox to revive the now unconscious Archer. Archer asks Tucker to use Daniels' sensors to locate Silik while he and T'Pol visit Daniels' quarters to study the database that Archer saw earlier. It is gone. Silik escapes to Shuttle Bay 4, and refuses to surrender the device, so Archer shoots it from his hand. Silik opens the bay doors and freefalls to a waiting Suliban shuttlepod, and Archer asks Lieutenant Reed to seal off Daniels' cabin and any temporal secrets it may hold.