Carol receives a second chance at life when a new heart becomes available; Choi and Archer find themselves in hot water with an old patient; Halstead faces the consequences of the stolen trial medication.
Phillip and Elizabeth Jennings seem like any other American married couple, but they are actually highly trained Soviet spies, who must kidnap a high-ranking defector and return him to Russia.
Third-year med students begin their rotation in the ED, and Maggie keeps a careful eye on one of them; Manning, whose mom's health takes another decline, tries to cover up how she broke the rules to treat her.
US President Ronald Reagan has been shot. Elizabeth and Phillip are up against the clock and the FBI in trying to find out who is responsible and whether they need protecting.
Phillip is reunited with an old flame and the reunion leaves him questioning the nature of his relationship with Elizabeth. Meanwhile, Stan and Nina finally give in to temptation.