Wolowitz invites the gang over to his mother's house for Thanksgiving because his father-in-law, Mr. Rostenkowski, is coming and he's looking for a buffer. Sheldon resists because he likes routine of Leonard cooking a bad turkey every year, but he eventually relents and ends up bonding with Mr. Rostenkowski over beers and a football game. Meanwhile, Leonard and Penny get into an argument after she shares a story about a Thanksgiving she spent in Las Vegas with her old boyfriend Zack, whom she accidentally married there without realizing it. Chaos ensues when Zack arrives at the dinner to sign annulment papers, and Mrs. Wolowitz is too sick to cook.