A prolific novelist, Ambler delved less often into the short form. "The Army of the Shadows", from 1939, concerns a chance encounter near the Swiis - German border. Ambler sets the scene well, though the plot is average. "The Intrusions of Dr. Czissar", first published in 1940, is a collection of six short mysteries, all concerning the title character's involvement in Scotland Yard's handling of murder cases. These are more suited for light entertainment value than armchair detecting, though a couple lend themselves well to the latter activity. The final installment, from 1970, is "The Blood Bargain", about a coup in an unnamed Latin American country. I consider this to be the highlight of the book.