The Mastermind

In 1970 Framingham, James Blaine Mooney, an unemployed carpenter, hatches a plan to steal four Arthur Dove paintings from the local art museum. He borrows money from his parents and then borrows from his mother under the pretense it's for work, so he can pay three men to execute the robbery. The getaway driver backs out after stealing a car for the job.

J.B. drives two thieves, Guy Hickey and Ronnie Gibson, to the museum where the paintings are stolen. Gibson pulls a gun on a student and they beat a security guard as they escape with the loot. The crime is completed amid the chaos of the museum robbery.

J.B. briefly displays one painting in his living room to show off the haul, but quickly takes it down when his father, a local judge, criticizes their ambition. He builds a container and hides the paintings in a barn loft to keep them out of sight.

Police and the FBI begin questioning the Mooney family about the heist. They learn that Gibson named J.B. as the mastermind after his arrest during a bank robbery. J.B. denies involvement and asks his wife Terri to take their sons to his parents' house, though Tommy refuses.

Guy Hickey calls J.B. demanding more money to stay quiet. When J.B. brings their son Tommy to meet him, the encounter is revealed to be a trap set by an organized crime outfit. They abduct J.B. and force him to lead them to the paintings.

Under duress, J.B. cooperates with his captors and uncovers the location of the four paintings. The criminals realize his deeper involvement and understand he orchestrated the heist.

With his role in the robbery public knowledge, J.B. goes into hiding with Fred and Maude, two former art-school friends. Fred is excited by the story, while Maude privately suspects J.B. planned to use a professor as a fence to sell the paintings.

Maude confronts J.B., deducing the plan involved using their old professor as a fence. She urges him to leave. J.B. rejects Fred's suggestion to hide out at his brother's Toronto commune and instead moves toward Cleveland.

J.B. travels to Cleveland to stay with other friends, but discovers they left town the day before. He hitchhikes to Cincinnati in search of somewhere to lay low as the situation spirals.

News arrives that the paintings were recovered and returned to the museum. J.B. calls Terri to rationalize his actions, but she hangs up when he asks for money, signaling a fractured relationship and an unresolved outcome.

Unable to afford the bus fare to Toronto, J.B. steals an elderly woman's pocketbook and blends into a crowd of anti-Vietnam War protesters. The police violently break up the rally, and he is swept up along with the demonstrators.

J.B. is arrested as protesters are detained, with the police van driving away despite his objections. The sequence underscores the consequences of his escalating desperation and involvement in the heist.