After 10 years of marriage and two children, it seems that Greg Focker (Ben Stiller) has finally earned a place in the "circle of trust" of his uptight father-in-law, Jack (Robert De Niro). However, Greg is moonlighting with a drug company, which raises Jack's suspicions. As two clans descend on the scene of the young twins' birthday party, Greg must find a way through myriad misunderstandings to prove to Jack – once and for all – that he is worthy of being the next family patriarch.