Ghost Ship (Star Trek The Next Generation, No 1)

In 1995, a Russian aircraft carrier is destroyed by a mysterious creature that just as mysteriously disappears thereafter. Three hundred years later, Counsellor Deanna Troi awakens in her quarters from a nightmare in which she senses the voices of the crew of that Russian ship, whose life-essences were somehow absorbed by the creature that destroyed them. And the nightmare heralds a danger to the EnterpriseTM itself, for if Picard can't discover a way to communicate with the creature, it could absorb his crew just as it did the Russians.