Q hurls the Enterprise into the path of the Borg.
Q appears with an offer to join the crew, which Picard flatly refuses. In response, Q flings the Enterprise some seven thousand light-years across the galaxy to meet something that the Captain is unprepared for, the Borg. Guinan reacts with fear on seeing the new foes, as she had encountered them before.
The Borg are a collective of cybernetic beings who assimilate other species and their technology. The first contact is brief but deadly, with several crew members killed. This episode introduces one of the most famous enemies in the franchise, and it sets up the later story of Locutus. It is an essential chapter for fans, and it shows how outmatched the Federation really is.