"At first it may seem an astounding coincidence that two members of a family should have considered it necessary to ask for the services of the same detective agency. I think I can prove otherwise, and even if I can't, the facts remain. Alice Stonhill and Peter Wesslake did precisely what I have said, and what's more . . ." So Ludovic Travers says at the opening of a case in which he joins with Bill Ellice and Superintendent George Wharton...