'The King Of Marvin Gardens' is a dark drama about two brothers who team up for an odd real estate scheme involving a Hawaiian island. Jason (Bruce Dern) summons his younger sibling, David (Jack Nicholson), a Philadelphia radio personality, to join him in Atlantic City to get the deal going. But when David arrives, he finds that a local crime boss has had Jason thrown in jail. David intervenes on his brother's behalf and succeeds in bailing Jason out. But the charges won't be dropped unless Jason forgets the Hawaiian venture.

So, together with Jason's girlfriend, Sally (Ellen Burstyn), and Jessie (Julia Anne Robinson), the two brothers try to figure out what to do next. One meeting with the crime boss convinces David that they shouldn't go through with their plans, but Jason won't hear of that. Something has got to give...