Their consciousness were ripped from their bodies and left in the harsh storms as anionic energy to suffer an eternal Hellish sentence in this strange type of prison. They can possess any lifeform, biological or artificial (like androids). They tried to escape twice. The first time was via the ship and crew of the USS Essex in the 22nd Century, but due to the technological restrictions of the time, they could not escape. The second was the USS Enterprise NCC-1701-D. Jean-Luc Picard and his crew outwitted them and forced them to return to the moon. It's assumed that Picard put a quarantine on the moon to prevent further encounters with the prisoners.