Poltergeist: The Legacy - Season 3 - Eps 11: Irish Jug
Kat is on the job when the team is put in charge of cataloging and disbursing the bequeathed estate of Hanney Ellen Keane and Derek makes a grave error. Taking a few drinks from a cursed Irish Jug causes two ne'er-do-wellers escape from the Jug and possess Derek and Milo. Once the boys realize what year they're in and the fortune the one called Derek possesses they soon decide to stay awhile but before they can enjoy the riches they must get rid of the women. Being the only one that sees the two impostors for what they are Kat must think quickly and convince Alex to help her as Rachel is nowhere to be found.
About Poltergeist: The Legacy

Title: Poltergeist: The Legacy
First Air Date: 1996-04-21
Last Air Date: 1999-11-12
Status: Ended
Rating: 6.1/10 (from 33 votes)
Language: EN
Seasons: 4
Total Episodes: 88
Network: Showtime
Genres: Sci-Fi & Fantasy
Production Companies: Trilogy Entertainment Group
Synopsis
The adventures of the members of a secret society known as the Legacy and their efforts to protect humankind from occult dangers.
Cast

Derek de Lint
Derek Rayne, Ph.D.

Martin Cummins
Nick Boyle

Helen Shaver
Rachel Corrigan, MD

Robbi Chong
Alexandra Moreau

Kristin Lehman