The unknown intelligence behind the ring of spatial distortion that enveloped Voyager in 2372, rearranging its decks while copying the ship's database and leaving a vast store of its own data.
In the episode Twisted, Voyager is caught inside a ring-shaped distortion while most of the senior staff are at a party for Kes's second birthday in the holodeck resort. Corridors begin to lead to the wrong places and the crew cannot reach the bridge or engineering.
Every attempt to break free makes the effect worse, and the ring slowly closes in on the holodeck where the crew have gathered. Tuvok argues that nothing more can be done, and Janeway, who has already been touched by the phenomenon and left briefly incoherent, comes to believe it is trying to talk to them.
The ring passes through the ship and everyone aboard without harm and then moves on. Afterwards the crew find that the entire computer library has been copied and that some twenty million gigaquads of new information have been deposited, suggesting an exchange between explorers.