Hallucinations of a wormhole leading home trap Voyager in an alien beast that consumes starships and incapacitates most of its crew.
5-07: Infinite Regress
A Borg vinculum stirs up the memories of every victim Seven of Nine helped to assimilate, leaving her to exhibit multiple personality disorder.
5-04: In The Flesh
Voyager encounters an exact replica of Starfleet Headquarters on Earth; a training facility for an invasion.