10 Moments Of Star Trek Foreshadowing You Never Noticed
9. The War Between The Borg And Species 8472
The Voyager episode Scorpion introduced Species 8472, an empire of highly intelligent, three-legged aliens from another dimension known as fluidic space. When the Borg first encountered Species 8472, they predictably tried to assimilate them, but the unique biology of life in fluidic space made this very difficult. Species 8472, under attack by the Collective, began a long, brutal war against them and all other life in the Milky Way Galaxy.
It was very interesting to watch the Borg go against such a powerful force. At this point, the Borg had never been threatened this much by any species. What you may not know is that the invasion of Species 8472 was actually foreshadowed a few episodes prior.
In the episode Unity, Voyager encountered a damaged Borg Cube in space. When investigating the Cube, the crew began to speculate that it was disabled by an attacker, which really surprised everyone because they couldn't imagine an empire more powerful than the Borg. They never found out who the attackers were in the episode, but Brannon Braga, a writer of Voyager, confirmed in issue 28 of Star Trek Monthly that the events of Unity were explained in Scorpion, heavily implying that the attackers were Species 8472.