Sabrina casts a spell on Harvey that makes him a great guitar player, which leads to him getting invited to play with the Archies.; Sabrina inherits the spooky Dumesbury Mansion from her Uncle Thaddeus. When she gets there, she finds that her powers don't work and that someone is trying to drive her mad with gas and spooky organ music.; The family's hippie cousin Bert returns from Salem University to teach everyone about non-conformism.; Sabrina puts a spell on Archie that turns him into a great basketball player.