When Leonard, Penny and Bernadette learn that Amy is going out on a dinner date, the trio set out to spy on her and the guy. Meanwhile, Sheldon recruits Raj and Howard to find a woman for him, since they were responsible for getting Amy and him together.

Sheldon has a revelation when he realizes why a song was stuck in his head. Also, Amy invites Dave over for dinner despite their previously awkward date, and Wolowitz and Koothrappali become obsessed with a fan of their band, "Footprints on the Moon".