On the 100th episode of Medium, an infant is kidnapped and Allison investigates the disappearance. But when she becomes too obsessed with the infant, Joe starts to get worried about her. Meanwhile, Bridgette and Joe are surprised after Marie manages to play the clarinet without any issues even though she hasn't attended any classes, while Bridgette is struggling to play.

Samples of a lethal viral disease vanish, a dire development that pushes Allison to tap into her extrasensory ability to foil a possible large-scale bioterrorism attack. Meanwhile, Scanlon prepares to pop the big question to Lynn (Tina DiJoseph), but Bridgette's visions indicate that their relationship could meet an ill-destined end

Allison and her daughters dream of the same mysterious girl who may be linked to the bizarre serial murders of entire families. Joe and his boss find themselves at odds while working on a major project.

When Allison begins having flashes to a specific time in the future, her sense of dread grows as she feels more and more powerless to stop a catastrophic event from occurring.

Allison's visions about the convicted sex offender new to her neighborhood have her questioning his guilt, even though her neighbors are furious about him moving in. Plus, Joe's potential career opportunity doesn't mesh with Allison's professional future.