Once upon a time I stumbled across a shelf of Green Penguin Books and couldn't resist buying several titles.

This book was first published in 1931 and was reprinted multiple times by Penguin Books starting in 1950. Ms. Allingham was a prolific author and started writing mysteries as a teenager. A subtle complicated mystery with a very unusual plot, and features her go to detective Albert Campion. I will definitely be hunting down more of her books and look forward to reading more from this author. Hopefully they will all be green Penguins.