Boots

"Do you want me to show you how I did it?" 
Frank Marriott is eager to confess to his wife's murder. He has both motive and opportunity, and his account of the night appears perfectly coherent. Yet Chief Detective-Inspector Alleyn is not convinced that a confession this complete can be entirely truthful.
In Boots, Ngaio Marsh distills the detective story to its essential mechanics, where the smallest, most ordinary detail becomes the key to an elaborate deception.