Raj and Howard's feud continues as the gang plan Halley's first birthday party. Sheldon's surprise for Amy's birthday goes awry when they get food poisoning. Also, Leonard gets a Christmas letter from his brother that causes him to spiral out about his own lack of accomplishments.
Casts:
Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg, Kunal Nayyar, Melissa Rauch, Mayim Bialik