The Rubber Band by Rex Stout

What do a Wild West lynching and a respected English nobleman have in common? On the surface, absolutely nothing. But when a young woman hires his services, it becomes Nero Wolfe’s job to look deeper and find the connection. A forty-year-old pact, a five-thousand-mile search, and a million-dollar murder are all linked to an international scandal that could rebound on the great detective and his partner, Archie, with fatal abruptness.