Thomas Fitzwalter, a young builder, is waiting in a site porta cabin to price a job when he is a witness to an assault on a young woman. Through the porta cabin window Thomas captures images of the assault with a camera he has with him. One of the images is of a charismatic American preacher, so called, who is standing in the doorway of the trailer angrily gesticulating at the woman. The builder intervenes and a fight occurs in which he holds his own against the woman's assailant but when a second thug appears on the scene - from out of the blue - Thomas is overwhelmed by the bigger man. His quietus is approaching but he is saved from serious injury by the woman who takes off one of her shoes and using it club fashion batters the thug into submission. The consequences that follow from the fight unfold against a backdrop of building site values, police corruption, religious hypocrisy, various human relationships and social events, all of which have a bearing on one of the most dramatic Saturday nights Thomas has ever experienced.