Farscape/Recap/S04 E11 Unrealized Reality

Season 4, Episode 11:

Unrealized Reality
While studying a wormhole in EVA, Crichton gets sucked down it and deposited in the private dimension of a powerful being he nicknames "Einstein". It's revealed that Einstein's people are of the same race as the Ancients, who were "substantially modified" to exist in Crichton's realm in order to monitor and "influence" the state of wormhole technology. After contact was lost with the Ancients, Einstein was tasked with investigating the current state of the realm's wormhole knowledge: finding a a Pathfinder beacon he dragged the beacon-bearing ship down a wormhole, only to discover that the ship he'd retrieved was actually Moya. After questioning the crew at length, he learned about Crichton and his fascination with wormholes, and has spent the last year tracking him down.

During this encounter, Crichton gets a crash-course in wormhole physics, and discovers that wormholes connect not only different points of space, but different points in time, allowing for someone traversing wormholes to travel backwards and forwards in time and potentially cause paradoxes. Crichton also witnesses the phenomenon of "unrealized realities" -- universe where events occur radically different as a result of meddling with time and space via wormholes. Einstein sends him to several of these unrealized realities, including one where the identities of Moya's crew are hopelessly jumbled from one character to the next ; another where Crichton is a Peacekeeper officer interrogating Sikozu, a Scarran spy; and one where the Scarrans conquered Earth many generations ago and interbred with the human population, resulting in versions of Crichton and his father that are quite clearly Scarran hybrids.

As he talks withCrichton, Einstein becomes convinced that Crichton can be trusted with his wormhole knowledge, and gives him the Ancients' old mission of preventing hostile forces from gaining wormhole technology- for the moment anyway. Finally, he imparts some knowledge that allows Crichton to traverse a wormhole in only his EVA suit. However, when he arrives on the other side, he's not back at Moya -- he's in orbit around the Earth...