It's 1971. William is 19, he's working in a dead-end job at London Zoo, and his dreams of becoming an artist are fading fast he left school with no qualifications and he can't get a grant to study at Art College. He feels as trapped as the orang-utans he's meant to be looking after.So when his best friend and fellow aspiring artist 'Daisy' Dave hatches a plan to travel through Europe to Morocco to sell LSD to the burgeoning hippy community there, William leaps at the chance. How else will he ever realise his dream? It isn't long before things start to go wrong. Daisy Dave vanishes after a bad trip somewhere near Paris. Then, in Barcelona, William gets drunk, steals a moped, and beats up a policemen not a good idea in a Fascist state. He's thrown into the city's notorious Modelo jail, where he joins a mix of hardened criminals and hippies like him. Hopes of a quick release are dashed when it turns out the policeman has suffered serious head injuries, and William must reconcile himself to a long captivity.

Tormented by remorse and self-hatred, and treated like an animal by the brutal prison guards, he spirals rapidly into depression. Only two things help: Mike, his American cell-mate, a cannabis-dealing Zen master who has been in Modelo so long that most of his teeth have fallen out; and the sketch book in which he obsessively records the visions and nightmares and the long-repressed memories that swirl inside his head...