Fear of Fear and Fear Itself

A bug is found in the re-materialization as Ulrich is trying to get back to Earth, leaving him stuck on Lyoko longer than his friends. Once back Ulrich starts to lose the line between reality and memory as Xana uses a painful time in his past to trap him as a little boy. Can Jeremie and Odd figure out what Xana did in time to keep their friend out of trouble?