chunk: The Borg sphere generates and enters a temporal vortex. As the Enterprise is enveloped in the vortex, the crew briefly glimpses an Earth populated entirely by Borg. Picard realizes that the Borg have used time travel to change history, and orders the Enterprise to follow. The Enterprise arrives in the past, on April 4, 2063, the day before humanity's first encounter with alien life after Zefram Cochrane's historic warp flight. The Borg sphere fires on the planet; the Enterprise crew then destroy the sphere and, realizing that the Borg were trying to prevent first contact, send an away team to the Montana missile complex where Cochrane is building his ship, the Phoenix, to look for survivors. Picard sends Cochrane's assistant Lily Sloane to the Enterprise for medical attention, then returns to the ship and leaves Commander William Riker on Earth to make sure the Phoenix's flight proceeds as planned. The Enterprise crew sees Cochrane as a legend, but the real man is reluctant to assume