To save a beloved restaurant from closing, Stan must bring the 1950s back to Langley.

Sam learns some things about her family.

Sam makes a choice.

While investigating the death of an intruder at Quantico, Jimmy and Kasie are exposed to a deadly biotoxin, and the NCIS team calls on Doctor Carol Wilson for help as they race to find the antidote. Also, Torres tries to distract Jimmy’s daughter, who came to the office to spend the day with her dad.

As the bomber is revealed, Layton comes to terms with his past decisions before making an irreversible call.

Clayton visits the hometowns of his final four women to meet their families and immerse himself in each of the ladies' lives.

Now that Shaun has called off the wedding, he is forced to confront Lea about their relationship and determine what he really means to her. Meanwhile, the team debate their opinions on plastic surgery and Dr. Audrey Lim hopes to expose Salen’s cover-up over an infant’s death to take her down before it is too late.

Jimmy breaks down basic arithmetic using pop-culture references and notable names in Popular Mathematics, then catches up with Kate McKinnon and Paul Dano before enjoying a musical performance from YG featuring Moneybagg Yo.