Through a series of misunderstandings, Alvin, Simon and Theodore come to believe that Dave is going to propose to his new girlfriend in New York City - and dump them. They have three days to get to him and stop the proposal.

Through a series of misunderstandings, Alvin, Simon and Theodore come to believe that Dave is going to propose to his new girlfriend in New York City - and dump them. They have three days to get to him and stop the proposal.