The Enterprise is transporting to the neutral planet Parliament peace delegates from two races which can't stand each other long enough to occupy neighboring suites, yet both want to join the Federation. Traveling trough a mysterious energy cloud, some gets aboard and keeps jumping from crew members to machinery and vice versa, as if seeking a suitable host and learning about the ship, without revealing itself. The crew catches on slowly, as nobody seems seriously affected, except Wesley's engineering mentor Singh, who is killed in a warp technology accident, but 'host' the highly intelligent entity.
Did You Know?
The first episode to reveal Data's persona of Sherlock Holmes. See more
When Geordi bends over Worf to check his pulse, the rubber outline of the makeup is clearly visible between his left eye and ear. See more
I admit some of my people are impulsive. And we all have reason to hate the Selay.
Lieutenant Tasha Yar
They appear to have the same feelings about you, sir.
Ah, the nature of politics.
Star Trek: The Next Generation End Credits
Composed by Jerry Goldsmith
and Alexander Courage See more