Middleton prepares to make wishes on Posner's Comet, but Cassie worries that a wish won't control big changes ahead, specifically when Sam is offered a dream job across the country. Grace prepares for her valedictorian speech, while Nick becomes unex... (more)pectedly nostalgic as high school concludes. Abigail plans a trip to Europe to forget about her breakup with Donovan, while Donovan tries to disprove the power of curses and win her back. Meanwhile, Martha struggles to make amends with her nemesis, and Stephanie and Adam are overwhelmed when their food truck is an instant sensation.