Josh and Jess have been happily married for 8 years. They are financially secure professionals with one dog and no children. They live in an upper middle class suburban neighborhood. One evening when walking home from dinner with friends they speak somewhat covertly about an unseen box Jess is carrying under her arm. Josh insists they must dispose of it immediately while Jess argues the opposite. She suggests that it has been a long time since they have engaged in this sort of activity and feels they can handle it now. Josh finally reluctantly agrees.
They enter their home and after Jess engages in some hysterical preparation antics and lots of ground rules are set, Josh opens the box. The viewers finally see the contents of the package, Jigsaw puzzle pieces falling on a table fill the screen. A plan for a competition is established where the first to complete their half of the puzzle wins. When they reach the last few pieces, it is apparent that each has one piece missing. After an exhaustive search finding the missing pieces appears to be a lost cause. and accusations begin to fly with each accusing the other of hiding their piece in order place the last piece first.
We watch as each one systematically tears through different rooms and possessions of the other in an attempt to locate it. After several hours, their home looks as though it has been struck by a natural disaster. They are so distraught that they conclude a divorce is the only solution.
The doorbell alerts them to the arrival of the neighbors, John & Sarah, who originally gave them the puzzle at dinner a week ago. They wander through the house alarmed and assume that a robbery has taken place.
The films final moments are filled with surprise, humor and exciting action.