Dr. Sturgis recommends Sheldon and Missy for a university research study on twins and Mary is unhappy when the test results go to Sheldon’s head.
Charlie tries to sweet talk Judith's divorcee support-group into letting Jake continue to spend weekends at his place.
All reassess their personal lives after witnessing a chance reunion between two long-lost lovers in the emergency room; Karev treats a troubled teen (Demi Lovato); Meredith shares her suspicions with Cristina.
When a modern-day prospector is found dead near a mining site and Lisbon is injured during the initial stages of the investigation, Agent Hightower joins Patrick Jane in the field for the first time.
Doug sabotages Carrie's efforts to socialize with her co-workers by doing crass things, such as showing them his chest hair. Amy Stiller guest stars.