Roger Querrin (who has either read no GAD fiction or is just plain stupid) decides to challenge the family ghost by spending midnight alone in the Room in the Passage of the ancestral home. Family friend Inspector Castle is recalled from his leave by Scotland Yard and so asks his friend Algy Lawrence “who could tackle the bizarre and the fantastic with expert skill” to take his place.
The plan is that Algy and Roger’s brother, Peter, will wait at the end of the Passage leading to the Room, whilst the local policeman Sergeant Hardinge stands guard outside the house. Despite their best efforts, on the stroke of midnight a scream comes from the Room and having shot out the lock Algy and Peter find Roger dead with a dagger in his back. The windows are still bolted and Hardinge has seen no one entering or leaving from the outside.
The only other residents of the house are Roger’s fiancée, Audrey Craig, and her uncle, along with a butler and a maid. Oh, there was also a prowler in the grounds earlier that night who gave Algy a good whack on the head before disappearing.
If this wasn’t enough a second impossible crime ensues before the pieces come together for Algy and he is forced to take desperate measures to catch a cold-blooded killer.
Lawrence and Castle have their riff on the Locked Room Lecture and reference both Death from a Top Hat (a real life case in their world with Clayton Rawson being the joint pseudonym of Merlini and Harte) and The Hollow Man. There is also a definite spoiler for The Big Bow Mystery and a vague detail about Rupert Penny’s “Sealed Room Murder” (which I will be reading soon).
I picked up on various clues as to who the killer might be but did not take the one step that could have lead me to the truth of the matter. I was slightly disappointed because I have seen this so well reviewed elsewhere but also because I was so pleased by “Death from a Top Hat” read only a few days before and this book could not match that.
I also had another realisation that in this type of mystery where no one could have done it, you generally don’t get the same type of surprise that Agatha Christie often pulls off where plenty of people could have done it, but actually the one person who couldn’t have done it actually did it.
A nice post-script in the Locked Room International version is correspondence between Smith and Doug Greene and Tony Medawar where he suggests a fix for a minor weakness in the story.