"The 45 Steps", by Peter Crowther

From: The Mammoth Book of Perfect Crimes and Impossible Mysteries, ed. Mike Ashley. Carroll & Graf, 2007.

There was only one thing noteworthy about the Regal Hotel in Luddersedge. Not the elegance of its ballroom, which was really rather threadbare; not the quality of it's foie gras, as the cuisine tended towards tradional English; certainly not the long list of distinguished guests who'd stayed there. No, the only reason to remember the Regal was the opulence of the gentlemen's lavatory in the basement.

Arthur Clark's bathroom habits were equally well-known around the village. At ten o'clock every evening he would get up and head to what Max Reger called "the smallest room in the house", whether he were in his own home, or at the Conservative Club's Christmas banquent at the Regal. So regular were his habits, in fact, that they could be used against him, and one of the elegant stalls in the Regal's restroom could in fact become the setting for a locked-room murder.

This rather droll story was original to the book in which it appeared but deserves wider attention. A mixture of dark humor, fair-play detection, and the character of irascable Detective Inspector Malcolm Broadhurst combine to make this a delightful exercise in classic detection.