Megan's last-minute visit shakes Michael when his mother objects; Brittany's party takes a turn when her ex arrives, and she's forced to reveal her secret; Scott has a big surprise for Lizzie; Clint gets a shocking phone call from Tracie.

Sarah's shocking discovery sends her racing to meet Megan. Tracie triggers Clint's epic meltdown. Scott & Lizzie unravel over a major blow-up. Marcelino stuns Brittany with a surprising offer. Caitlin gets a devastating call from Matt.