Weird Science - Season 3 Episode 16 -

When Lisa performs a seance, it of course doesn't go right. Chett brings, Uncle Baldash, a member of the Donnelly family back to life. Uncle Baldash was a warrior during the 1100s. Chett loves his new uncle and goes back in time in order to live as a warrior. This means that Wyatt has to go back in time to save Chett from getting killed.