But We Didn't Get the Fox (1969)

Richard Llewellyn, the Welsh author of How Green Was My Valley, published this espionage novel with Doubleday in 1969 as the second of his espionage novels featuring Edmund Trothe. With trouble in his company's Cairo office and its staff under threat across the Middle East and in Rome, Trothe hunts the people behind them, among them a man called Mariotti, whom he finally tracks to a farmhouse in northern France. (Open Library)

Watches

Patek Philippe watch: Posing as Henri Dumesnil, a buyer for a crop broker, Trothe plants three explosive stickers on Mariotti's farmhouse and times them by the second hand of his Patek Philippe: they should have blown at twenty to thirty seconds, and at fifty nothing has happened. He goes back to the car and sets the device carried in the thin Patek Philippe, a circuit running round the inner rim, by pulling the crown, turning the hands to midnight and back; then he keys his F25 transmitter, and the house shudders. He checks the Patek again on p. 318, and before travelling in disguise as a Bedouin he leaves it in the safe and wears a large gold wristwatch instead (p. 337). The circuit is the novel's spy device. The maker is named; the model is not.

Source text: I went back to the car to set chx. Mine was in the thin Patek Philippe wristwatch, with the circuit running round the inner rim. I pulled out the winder, turned the hands to midnight, pulled it out further, turned it forward, and twice back again, and I was ready. (Richard Llewellyn, But We Didn't Get the Fox, scan cataloged as Doubleday, 1969, p. 313, where the timing check with the Patek's second hand comes earlier on the same page; "chx" is as printed in the OCR; Internet Archive scan OCR)