A desensitized-to-life, nihilistic, high-fashion photographer Thomas (David Hemmings) in London, who lives a mid-60s life of excess (riches, fame, and women), becomes bored with his lucrative career of glamour photography. So he resorts to photographing, in documentary style, the seamy and sordid side of life in London, in flophouses and slums.
Innocently, he takes candid photos in a deserted park of a lover's tryst-rendezvous between a kerchief-wearing woman (Vanessa Redgrave) and a middle-aged, gray-haired man in a light-gray suit. She pursues him to ask for the illicit photos, as he imagines that he has witnessed a scene of sexual intrigue - never thinking that he may have accidentally obtained visual, criminal evidence of a murder.