After a brief appearance from Megadroid, we see Chuck D Head and Igor fighting in Castle Frank N. Stein. Igor has come to fetch Chuck, since Professor Frank N. Stein needs him in the lab, but Chuck won't go. They fall off a ledge, but Chuck holds a rope while Igor falls to the floor of Frank's lab. Soon, the rope Chuck's holding frays and snaps, sending him plummeting to the ground, landing on top of Igor. Soon, Chuck is strapped into a chair, where Frank reveals he will remove Chuck and Head's brains, stick them together and put them back into Chuck. As Frank prepares to make a 'delicate incision' with a chainsaw, the doorbell rings. Detective Case is here and he's looking for a missing person.
Case is investigating the disappearance of a double-glazing salesman and instantly suspects Chuck. In another room, Igor is forced to admit it was he who killed the salesman. He recalls the time where Frank asked him to go out and dig up a fresh corpse for another experiment. Igor is reluctant to go out into the rain but when a salesman comes to the door, he invites him under the pretense of being interested in replacing the stained-glass window. With the salesman's back turned, Igor picks up his shovel and kills him, allowing Frank to create life. It happens that that life was Chuck and he isn't happy.
Chuck and Igor fight about Chuck being a failed experiment, though Frank admits he was a successful one, Richard and Judy being among some of his failures. Detective Case bursts into the room as they fight, causing them to pretend to be ultra-casual. Frank denies having any knowledge of the salesman, but when Case presents a leaflet for double-glazing, Igor admits who did it; Chuck! The re-animated corpse tries to explain that he was the one who was killed and was brought back to life but Case doesn't believe him. Pulling out a gun, he chases after Chuck, dragging Igor with him as a navigator of the castle.
Chuck and Head continue to run through the dungeons, passing the Blockbusters contestant from the first story, until they reach a dead end. Thanks to Igor's help, Case reaches them. As a last resort, Chuck fires Head towards them, but at Igor. Case points out that he has a gun and Chuck should have aimed at him, which Chuck quickly realises. As Case gets ready to fire, Chuck tries tough-talking and it seems to work, sending Case off running. However, Head looks behind him and sees a giant sewer monster ready to attack...
Head stutters to get a warning out but it's too late; the monster chomps the pair up whole. He munches until coming to a hard bit of food, Head, which he spits out. Content, the monster sits back until his stomach starts fighting back and Chuck is spewed out. The monster is quite apologetic, yet refuses to ear Igor when Chuck asks him. As Chuck runs off, Case finds him again. To hide, Chuck retreats into his bandages. As Case jumps in to find him, Chuck re-emerges, knocking the policeman out.
Back in Frank N Stein's lab, the professor pulls the top of Detective Case's head off and removes his brain. He then proceeds to hit with a mallet, stretch it out with his teeth, blends it in a beaker of acid, electrocutes it and pulls it through a mangle, all in an attempt to erase Case's memory. "Several hours of pushing and cramming" later, Case is sent on the way, with the treatment seemingly successful. However, as Igor moves to put sugar on his grapefruit, Case's brain talks back to him from the plate. It looks like they've sent Case back to the police station with a grapefruit for a brain. The brain asks them all to accompany him to the station...once he figures how to move, that is.
- Detective Case looks a lot like Bruce Willis.
- Megadroid makes his final appearance in a story that is not his own.