Amy gets phone call, and the face she's making probably suggests that it's a puzzling conversation with Sheldon, who she's been recently reunited with.
Sheldon makes an important phone call. He's been trying to figure out why a certain song is stuck in his hand, and that brings him to a revelation. Could that have something to do with Amy?
Sheldon: I'll have a diet Coke. Penny: Can you please order a cocktail? I need to practice mixing drinks. Sheldon: Fine... I'll have a virgin Cuba Libre. Penny: That's... rum and Coke without the rum. Sheldon: Yes, and would you make it diet?
