Stone

Members of the Grave Diggers motorbike gang are victims of a series of spectacular and horrific killings after one of the gang has witnessed the assassination of a political leader at a rally. Stone [Ken Shorter], is sent to join the gang, in order to investigate the murders. The gang recognise him as a 'pig' and are immediately suspicious until he proves his good intentions by following another murder attempt against them. They take a vote and, reluctantly, Undertaker, their leader [Sandy Harbutt], accepts their decision to let him join them. The following day, Stone's skill on a bike is put to the test in a hair-raising race sequence after which he is subjected to a humiliating initiation ceremony. Stone finds himself strangely drawn to the Grave Diggers' life-style and finds himself torn between his affection for them and his duty as a policeman in the final confrontation between the gang and the assassins.