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".
Elenco:
Jim Parsons
,
Johnny Galecki
,
Kaley Cuoco
,
Simon Helberg
,
Kunal Nayyar
,
Mayim Bialik
,
Melissa Rauch
,
Kevin Sussman
,
Aarti Mann
,
Kevin Sussman
,
Sara Gilbert
.