CASS is based on the true story of the life of Cass Pennant, adapted from his book. The film tells of how he was adopted by an elderly white couple in 1958 and brought up in SLADE GREEN, an all-white area of London. CASS is forced to endure racist bullying on a daily basis from local children, who also ridicule his feminine sounding name, "Carol", a name give to him by his Jamaican biological parents. Cass adopts his new nickname after the boxer CASSIUS CLAY. His adoptive father starts taking him to see West Ham United on a regular basis, and he becomes involved in hooliganism aged 14 after helping the INTER CITY FIRM, THE WEST HAM HOOLIGAN FIRM, fight Wolverhampton Wanderers supporters in 1972.