'The Bromsgrove Venus', originally transmitted on ITV, 15 March 1968
Written by Anthony Skene, Directed by Jim Goddard

Marker visits the public library, where there is an exhibition of photographs from a recent competition. One photograph, a nude woman posed after a Velasquez painting, stands out. The shocked chief librarian, Ainsworth, later confides that the woman is his wife and that, according to the records, the picture was entered by his assistant, Ingleby. Marker reluctantly agrees to investigate.

Marker visits Ingleby's flat, but soon realises that Ingleby did not take the photograph and is also a homosexual. Meanwhile, a troubled Ainsworth finds smaller prints of the photograph in his wife's handbag.

Having ruled out an affair, Marker visits Ridge's, Ingleby's photography suppliers. He notices a display of candid photography, and is told that one photograph, a female nude, was stolen. Suspecting Ingleby, Marker returns to the library and confronts him. Travelling with Ingleby to Ridge's, he obtains an address for the person who ordered the prints, a post-box at Nora's Tuck Shop.

At Nora's Tuck Shop, Nora is uncooperative. Meanwhile, Mrs Ainsworth, fearing her husband knows of her secret and plagued by a blackmailer, begins her own investigation. At the library, however Ingleby lies to her, telling her the photograph has been stolen.

Ainsworth refuses to let Marker question his wife, and talks of dropping the case altogether. Marker follows Mrs Ainsworth to Nora's Tuck Shop, where she bribes Nora and is given an address. Marker follows her to a branch of the Church Militant Union, but loses her when she jumps into a cab.

Marker returns to his office, where Mrs Ainsworth is waiting. She tells him that seven years ago she had a brief affair with a sailor, Philip Busby, who took the photograph. Someone has been sending her the prints and demanding £5 a month to keep quiet. Marker agrees to visit the address Mrs Ainsworth obtained from Nora. He returns to the Church Militant Union, and notices a dance school above it. Pretending to want dance lessons, he is introduced to the school's head, Mrs Busby.

The next day, Marker returns to confront Mrs Busby. When threatened with the police, she admits she was Philip Busby's wife. Left penniless, but still holding his negatives, she blackmailed Mrs Ainsworth for revenge and recompense. Mrs Ainsworth arrives (as arranged with Marker) they concoct an explanation for her husband's benefit. Ainsworth doesn't really believe it, but decides he prefers this explanation to the alternatives.