"The Penrose Mystery", fist published in 1936, is definitely up to the high standard of the wonderful Dr. Thorndyke series. Penrose is an eccentric old man in possession of some dazzling gems, which he won't insure. When Dr. Thorndyke is alerted to a burglary at his house, a scrap of paper is found with the word 'lobster' on it along with two Latin words. Meanwhile, Penrose has fled in panic after a car accident. The police believe he's gone into...