Jerry (Ryan Reynolds) is a packer in the factory, living with a cat and a dog. In the eyes of his colleagues, Jerry is optimistic and cheerful, and is full of enthusiasm for work, but in fact, Jerry suffers from severe schizophrenia and needs to rely on drugs to control his condition. What's worse, Jerry did not take the drugs as prescribed by the doctor! Because once he took the medicine, he couldn't talk to the cats and dogs at home. Jerry likes Fiona (Gemma Arterton), a female colleague in the advertising department. In an accident, Fiona died under Jerry's knife. Jerry took Fiona's body home, cut off her head and hid it in the refrigerator. What shocked Jerry was that Fiona's head began to speak, and Fiona begged Jerry to find a companion for her, so Jerry set his sights on Fiona's friend Lisa (Anna Kendrick).