Sheldon introduces his twin sister Missy to the guys, and all are attracted to her. Raj decides to take part in a drug trial to cure his inability to talk to women, and Leonard insists Missy stay with them at the apartment. Predictably, the men all awkwardly flirt with her, so Penny comes to her rescue. Leonard, hoping for an advantage over Howard and Raj, convinces Sheldon he is Missy's guardian as concerns her choice of partner. Sheldon deems all three guys to be unsuitable for her. On learning of Sheldon's plan to find her a suitable mate, Missy confronts her brother, and after she kicks him in the groin he agrees she can date whoever she likes. She turns down Leonard, and then Howard, who fails to charm her with simple conjuring tricks. Finally Raj goes to talk to Missy, who shows interest in him, but the drug wears off and he is unable to speak to her, forcing Raj to leave defeated.