Jeremy and Julian Lewis are two unruly brothers who terrorize Swansea from the caravan park where they live with their family. When their father, Fatty, is injured while working on a roof for local kingpin Bryn Cartwright, they try in vain to claim compensation. Thus begins a campaign of terror, which local policemen Terry and Grayo are ill-equipped to prevent, involved as they are in a drugs deal with Cartwright.