Star Trek: Voyager - Season 4 Episode 20 -

Bored with his daily routine, Tom Paris finds a refreshing friendship with a visiting alien willing to share a new method of propulsion with Voyager. Unwittingly, Tom finds trouble when his new friend swaps bodies and delivers him to authorities ready to charge Tom with the aliens' crimes. Meanwhile, the alien in Tom's body makes waves in Tom's personal and professional relationships on Voyager.