Archer and his new crew pursue the Suliban Cabal to return the Klingon courier Klaang and uncover the start of the Temporal Cold War.
The second half of Enterprise's pilot sends Archer's newly launched Enterprise NX-01 after the Suliban who have taken Klaang, the Klingon courier who crashed on Earth. With T'Pol assigned as science officer by the Vulcans, the crew tracks the Suliban to a huge orbital facility and recovers Klaang along with the message he was carrying.
Archer learns that the Suliban Cabal takes orders from a shadowy figure from the future, opening the Temporal Cold War arc that runs through the series. Klaang is returned to Qo'noS, and Starfleet agrees that the mission should go on. The episode sets up the uneasy partnership between Archer and T'Pol and Earth's first steps into deep space.