A rift in space that drains energy from ships caught within it, where the USS Brattain and later the Enterprise were trapped.
Tyken's Rift is a spatial phenomenon that absorbs energy from any vessel that enters it, leaving ships unable to escape under their own power. It also interferes with the dream sleep of humanoids, slowly driving crews toward paranoia and violence.
In Night Terrors, the Enterprise finds the USS Brattain adrift inside the rift with nearly all of its crew dead after turning on one another. The Enterprise is soon caught as well. Troi discovers that aliens trapped on the other side of the rift are reaching out through dreams, and the two ships escape together once the Enterprise supplies the hydrogen they need.