Michael, David and Micky enter old abandoned Mammonth Studios, where two sly con artists, J.L. posing as a movie director and his sidekick Harvey persuade them to do a movie portraying bank robbers and they're instantly dressed in suits carrying Thompson submachine guns. J.L. asks for photographs of them so Micky presents a baby picture of himself. Since the crook wants recent photos for publicity, Micky, using a camera on a tripod, snaps a photo of Michael and David with J.L. and Harvey which J.L. discards along with Micky's baby picture into the wastebasket. Then J.L. sends the guys to The Ninth National Bank to do a robbery scene claiming the cameras are hidden and tosses them some scripts of lines to use, telling them to ad-lib the rest. J.L. tells Harvey his scheme is foolproof: either they will get rich, or The Monkees will be caught and go to jail!
The guys hold up the band while David flirts with the cashier in between, get 50 grand, and return to the studio, amazed at the quality of their acting. They find Peter, who missed joining his pals for the great holdup scene since he had gone to stage 1 at 2:00 instead of stage 2 at 1:00. J.L. pays them each $100 and then tips off the cops. Later, When police converge upon the pad, Peter at first thinks its about his overdue book to which he opens the door slowly and slides the book out. When the cops still don't leave, The Monkees think it's another shooting; the Sergeant orders one of his officers to go in after the boys. The nervous cop enters the pad clutching a machine gun and attempts to apprehend the boys, stammering and shaking; Micky criticizes the cop on what he thinks is bad acting and gives him direction on how to be ruthless and steely-eyed. The cop leaves and reemerges to shoot up the place with a stream of bullets!
At the station house, shown the pictures of them taken by the banks automatic cameras, Micky, Michael and David-surprised the film print is black and white instead of color-still think it's just a movie. In a fantasy sequence, Peter enters with popcorn for the movie, while David is being blocked up a kissing couple and Michael by a woman with a large hat. Then the sergeant books them for armed robbery-which convinces The Monkees that their situation is real! They try to explain to him that they thought they're were shooting a movie but he doesn't buy it and soon has the trio in the interrogation room to interrogate them which just leads to comical antics as they put on sunglasses when the lights are shining on them and literally change their tune, spill the beans, each get the third degree and have the book thrown at them but all end up being charged for armed robbery and incarcerated. While in jail, Peter arrives bringing the guys some files (nail files!) and a lawyer. Both Peter and the lawyer believe they're guilty and the lawyer winds up charging them $40,000 plus carfare since they just robbed a bank and the three decide they need another lawyer.
At the trial, David, Micky and Michael act on their own behalves and each take turns with cross examinations wearing disguises with Michael disguised as a juror until the prosecutor exposes him to the angry woman judge where upon Michael manages to win her over by flattery and roses. Then Michael cross exams the vice president of the bank with nonsense questions and then David cross examines Micky in dragged disguised as his own mother. Soon the guys are causing chaos at their arraignment with their Monkee antics where David and Michael disguised as hot dog/peanut vendors selling to the crowd and handling dynamite that ends up exploding in the prosecutor's face leaving him practically blackened. Meanwhile, Peter dressed in a Sherlock Holmes-cap carrying a magnifying glass, enters the studio searching for clues. Harvey sees Peter taking a photo out of a wastebasket and, fearing it's the incriminating picture taken earlier of Micky, Michael, David and the hoods and it would blow their cover, Harvey informs J.L. over the phone.
J.L. orders Harvey to buy time until he arrives. Once there, he and Harvey try to get the photo from Peter which leads the two to give chase all over town set to "Pleasant Valley Sunday," and finally into the courtroom. The other three's hopes are dashed however, when the photo Peter has turns out to be the wrong one; it's the baby picture Micky gave to J.L. earlier and it appears the two criminals are saved. Then the judge is handed the picture, and, won over, she decides to exonerate the boys, and they celebrate their acquittal with a rousing rendition of "Randy Scouse Git."