In February's Season 3 premiere ... of "Ghosts" had no idea, "so we allowed the audience to be slightly ahead of the characters, which was a fun twist," says Port. Thursday's episode shows ...

Pete's ex-wife, Carol, shows up at Woodstone Mansion during Sam and Jay's Halloween party, where they're trying to impress some cool friends. Also, the ghosts hope to bring Flower back with a séance.