Jerry works at Milton, shipping and delivery department. He lives on his own above MELLOW, a rusty disused bowling alley. He has conversations with his dog Bosco and his cat Mr. Whiskers. One day, his manager compliments his work and chooses him to help organise an employee picnic and a conga line as Fiona suggested in a the meeting. During the preparations, the whole team is in a restaurant and he asks the English Fiona on a date. He invites her to the best spectacle in the world and she doesn't know how to decline. His therapist asks Jerry about his prescription taking.Friday night, Jerry watches a Chinese Elvis and a resurrected Bruce Lee while Fiona and the co-workers girls karaoke. On his side he leaves an unlimited Shi-Shan buffet and cross Fiona unable to get home. Jerry stops and gives her a ride. Jerry is in Heaven, everything is bright and Fiona is an Angel. Suddenly in the forest the car crashes into a deer. Jerry's hallucinations show the deer crying out in pain and begging Jerry to kill it, and so he slits its throat. Fiona, terrified, runs off into the woods. Jerry pursues her and trying to reassure her, he makes a lethal gesture. Apologising for hurting her, he ends her pain by stabbing her again and again. Sorry. Sorry. Upon returning home, Bosco tells him to go the police and confess, and that he is a good man who just made a mistake. However, Mr. Whiskers says there is no shame in killing, but insists Jerry needs to dispose of the body. Jerry goes back to the wood and rolls the immaculate Cinderella body into a carpet. The sheriff asks him about his car crash. At his appointment with his shrink, Jerry confesses that he doesn't take his meds at all. Back home, he dismembers Fiona and places her meat in Tupperware boxes, and her decapitated head in the fridge. After his work Jerry takes his pills, and has nightmares of his abusive past. When he wakes up during the night, his hallucinations have ended; his pets no longer speak to him, and Fiona's head is cold and rotten. He throws away the pills in terror, and the next morning, Fiona smells like a baby-shampoo again. After breakfast, Fiona asks for a friendly severed head to share her days, but Jerry insists that he can't. Butterfly and sparklers are back in Jerrys life. He didn't want to be a slave to drugs but he's still between Rosco and Whiskers.At the end of the next day at five, it's time to invite Lisa, a colleague of Fiona's from accounting, for a drink. He develops feelings for her and takes her to his abandoned childhood home, where it is revealed his German mother had confessed to her insanity and was about to be taken away by the authorities when he was a child. When they arrived, she tried to slit her throat, and begged Jerry to finish the job to end her suffering. Jerry sobs in front of Lisa, who comforts him. They go back to her house and spend the night together. He's in a dream. Lisa is on a cloud. When Jerry returns home, he still feels pressured into killing someone else by Fiona and Mr. Whiskers, and seems unsure of what to do next. Lisa interrupts the sinister meeting. She finds out Jerry's address through Milton's files and brings some cakes to his house. Inadvertently Jerry locks himself out. While he tries to get back in through the skylight, Lisa succeeds in forcing the door open. She sees Jerry's place in real dimension and wanders in and discovers the remnants of the bodies and Fiona's head on the living room table. Lisa says they can forget it and go back to normal. When she tries to leave, Jerry throws her aside and accidentally breaks her neck. Fiona now has a fridgemate. Other co-workers from Milton begin to wonder about Fiona and Lisa. When their colleague Alison goes to MELLOW, Jerry immediately kills and dismembers her. A new companion in the fridge and the voices add in the apartment.Jerry looks very bad. He falls apart in front of his counsellor Dr. Warren and confesses his killings but she tries to make a call. He takes her hostage into the countryside and forces her to help him. She calms him down and shows understanding, which makes him feel better. Ten years of therapy in ten seconds. Meanwhile, John and another colleague finds Alison's car behind Jerry's house. They break into it, they retreat immediately and call the police. When Jerry returns home, holding Dr Warren, cops surround his house and prepare to move in. Jerry flees down into the basement, breaking a pipe. Dr. Warren is taken to hospital. The police are knocked back when the pipe Jerry broke causes a gas leak, which leads to a huge explosion. Down in the bowling alley, Jerry collapses and dies from smoke inhalation.After a long corridor, in a white void, Bosco and Mr. Whiskers says Goodbye to each other. Jerry meets his parents, then appears with Fiona, Lisa, and Alison, and Jesus, and they all dance together. Sing the Happy song. Sing the Happy song. Come on clap your hands. Sing the Happy song.