Carole Laure wears a Vacheron Constantin

Alain Corneau's The Threat (1977), released in France as La Menace, is a psychological thriller built on a love triangle. Yves Montand plays Henri Savin, who has run a trucking company for years for his lover Dominique, played by Marie Dubois, while planning to leave her for Julie Manet, the younger woman he has made pregnant. Carole Laure plays Julie. When Dominique throws herself off a cliff, Inspector Waldeck decides Julie pushed her, and Henri plants false evidence to draw the suspicion onto himself and clear her.

The watch is identified as a Vacheron Constantin, but only by a single watch blog that gives no reference or image, and no model beyond the word 'Donna,' which is just Italian for a woman's watch. Vacheron Constantin is the oldest Swiss watchmaker in continuous operation, founded in 1755, and a ladies' piece from the maison would be a discreet and expensive thing. No circulating still shows the watch on Carole Laure's wrist clearly enough to confirm even the brand, so the Vacheron stays a plausible guess rather than a confirmed identification.