The rescue of a damaged transport prompts the Denobulan Phlox to confront his prejudices when he treats an Antaran, whose people are sworn enemies of Phlox's. Three other Denobulans are holed up in an underground cave, where Trip, Reed, and Mayweather are dispatched to retrieve them when militants take over a planet.

A scientific research team uncovered the remnants of an alien ship and two frozen cybernetic bodies in the arctic. These aliens soon thaw out and flee Earth, taking the research team with them. Starfleet orders Enterprise to find them, but nothing prepares the crew for just how dangerous these aliens really are - Borg drones