Swati Kapila

Sheldon and Bert collaborate on a research project, although Sheldon feels embarrassed to be associated with the study of geology.

Amy tries to convince Sheldon that he has a more laid-back side. Raj and Stuart compete to woo Bernadette's new colleague Ruchi.

Leonard and Howard learn that Sheldon went to work with the military behind their backs. Bernadette thinks Ruchi's trying to steal her job.

Irish Goodbye: Josh travels to Ireland to marry Clare so she can get a Green card and asks Liza to go with him. Clare asks Liza to support their relationship and insists that Liza owes it to him while Liza tells Josh she is uncomfortable lying to Homeland Security. Season finale. (S4, E12)

A Novel Marriage: Liza learns that Charles has considered removing her as editor of Pauline's book. Lauren invites Kelsey, Liza, and Pauline to an exclusive women-only club. While at the club, Pauline runs into an old friend named Louise who invites her and Liza to a highbrow party. (S4, E10)

An aspiring journalist working at a Boston newspaper receives life-changing news following a hospital visit.