Before telling McGarrett all he knows about Oahu's drug ring, Charlie Hazard (Kevin O'Connor) is gunned down on the steps of a church by Johnny Kling (Rich Little). When McGarrett arrives on the scene, Father Neill (Mel Ferrer) reveals that Hazard blamed himself for the death of a young girl whom he had rehooked on drugs. With this lead, Five-0 checks the records for recent overdose deaths and comes up with the likely victim, Makamea Maile.
Suspecting that this was not a gang killing, McGarrett visits the rehabilitation center where Makamea stayed, hoping to learn if there was anyone she was especially close to. The center manager, Tommy Saito (Jimmy Borges), says that she was so generally loved "like a sister," that no one person stands out from the crowd. As McGarrett leaves, he watches Kling do his impersonation act for the residents. Saito notes that Kling has been clean for three years and comes back often to lend support to those trying to quit drugs.
Within days, Kling confronts drug distributor Kellman (Milton Selzer), the second person he considers responsible for Makamea's death. The angrier Kling gets, the more he falls into the character of Jimmy Cagney, even demanding that Kellman call him Mr. Cagney as he pleads for his life. Then he shoots Kellman three times, each shot intercut with a scene from the film Public Enemy, where a dead Cagney, wrapped like a mummy, falls through an open door.
Using a disguised voice, Kling tells McGarrett to come alone to a motel where he will learn more about Hazard's death. When Steve arrives, the phone rings and Kling tells him to first turn on the phonograph, then open the closet door. The song "I'm Forever Blowing Bubbles" fills the room as Kellman's trussed up body crashes to the floor.
Based on the motel manager's description of the man who rented the room, an HPD artist draws a likeness. McGarrett recognizes Johnny Kling. When Five-0 breaks into his room, they find it turned into a Cagney shrine. Kling's walls are covered with ads for a film retrospective now in progress at a local theater. Convinced that a clue to what will happen next will be found in one of those films, Steve and Danny head for the theater. On the way, they learn that drug boss Paul Thaylor (Don Knight) has been kidnapped at gun point. Rushing into the theater, they press the projectionist (Kwan Hi Lim) to show the last reels of each of the films. In one they see the final scene from Public Enemy; in the other, the "Top o'the world, Ma" scene from White Heat. They now know where to look for Kling and Thaylor -- at the local oil refinery.
Rushing there, they see a cringing, whimpering Thaylor and an exultant, cackling Kling on top of one of the storage tanks. Kling is so deeply into the role by now that he precisely replicates Cagney's words and actions in the film. McGarrett dodges his bullets and slowly talks him back out of his psychotic state, calling him by name and reminding him that Makamea would not have wanted him to do what he is doing now.
Thaylor is left sobbing on top of the tank as Kling slowly descends the metal stairway, the gun loose in his hand. As McGarrett takes it from his limp grasp, Kling looks up and sees the squad car headlights. Eerily he breaks into a little buck and wing as he sings "I'm a Yankee Doodle Dandy." Then he is led away.
NOTE: This is one of my all-time favorite Hawaii Five-0 episodes. Rich Little's performance is beyond praise. Milton Selzer outdid himself as the drug dealer facing death. And how delightful it was to see the normally cool Don Knight pulling out all the stops as a terrified drug lord. However, none of this would have been possible without a magnificent script. But what a strange credit line: "Suggested by a Story by James Breig." (NOTE: Karen Rhodes tells me that this is the only Five-0 episode based on a literary work. Has anyone ever seen the original? Does anyone have a copy? If so, will you share it with us?)
P.S. One explanation for Mel Ferrer's incredibly brief appearance as Father Neill is that he was already on hand for his slightly larger role as the evil Emil Radich in To Kill a Mind (episode 211, production number 0616), which was broadcast on March 17.