The Stranger

S4, E15: While investigating the disappearance of Leah Robinson, a churchgoing, suburban stay-at-home mother of a 12-year-old boy, the team begins to suspect that she may not be as innocent as her husband and minister think she is. Leah was last seen leaving a Manhattan gallery opening with a man who was arguing with her. When Leah's husband, Ken, is stumped as to the man's identity and Leah's reason for being at that city event, the team explores whether her disappearance could be linked to an affair gone awry. They also attempt to track down a disgruntled client of Ken's whom Leah had nervously kicked out of their home at gunpoint when the menacing client showed up and refused to leave before Ken returned. The investigation takes an unexpected turn when the agents learn that Leah had secretly followed her husband on his recent "hunting trip" and seen him with a waitress who was fatally shot days later by a pistol of the same make as the Robinsons'.