Regeneration (Star Trek: Enterprise)

"Regeneration" is the twenty-third episode of the third season of the science fiction television series Star Trek: Enterprise. It first aired on UPN on May 7, 2004.

The episode focuses on the Enterprise NX-01 crew's encounter with dormant Borg technology and cybernetically enhanced beings in the Arctic. A group of Borg drones, crash-landed centuries earlier in a sphere from the future (implied to be from the events of Star Trek: First Contact), are accidentally awakened by a group of scientists. The Borg begin assimilating the scientists and rapidly adapt to the environment, posing a significant threat to the Enterprise and potentially Earth.

The Enterprise crew, led by Captain Jonathan Archer, investigates the incident and confronts the Borg. They struggle to understand the Borg's technology and collective consciousness. Ultimately, the Enterprise is able to destroy the Borg ship before it can reach populated areas of Earth. However, the episode establishes the presence of Borg technology in the Delta Quadrant, hinting at the Borg Collective's eventual rise to prominence in the Star Trek universe and their future conflicts with the Federation.

The episode is notable for its introduction of the Borg to the Enterprise timeline, significantly earlier than their established encounter with the Federation in Star Trek: The Next Generation. This retcon was controversial among some fans due to perceived inconsistencies with established canon.