The Skeleton in the Clock by Carter Dickson

"What would be the most dangerously haunted place in the world?" This was the topic of conversation of Ruth Callice, an attractive young woman, John Stannard, K. C., an older man, and Martin Drake, a thin young man. The three eventually agreed that it would be the execution shed of a prison. They would go to Pentecost prison and spend the night. Pentecost had been an active prison until 1938 when it was closed and was currently being used for storage purposes. Stannard would use his connections with the prison commission, and get the keys for a night or two. Then Stannard recalled that Pentecost prison was near Fleet House, a Georgian house with a flat roof. Twenty years before, Sir George Fleet fell over from the roof and died on the ground forty feet below. There had been witnesses who swore that there was nobody on the roof at the time of his death. It was suicide or something else.

The next day Martin Drake attended an auction with his jovial, rotund friend Sir Henry Merrivale. Here Drake saw his long lost love, Jenny,  from two years before. They had fallen deeply in love on a short train journey and then had become separated as the train departed. He had been searching for her ever since; a search which was complicated since he didn't know her last name. Jenny in that time period had become engaged to Richard Fleet who was the son of Sir George Fleet, the man who fell from the roof. Chief inspector Masters had asked Sir Henry Merrivale to assist him in reinvestigating the death of Sir Henry because Scotland Yard had received letters implying that the death was not an accident.

Meanwhile at the auction, while the lovers were finding each other, Sir Henry had managed to poke Lady Brayle, Jenny's grandmother, in the rear with a halbard. Sir Henry and Lady Brayle then engaged in a bidding duel for something. Sir Henry was determined to obtain the object, whatever it was, and outbid her. He did succeed and found himself the owner of a grandfather's clock with a skeleton inside.

Thus, after all of these preliminaries, the reader finds all the characters assembled at either at Fleet House or in the pub across the road from Fleet House. Inspector Masters and Sir Henry to investigate a twenty year old crime and Martin Drake, John Stannard, and Ruth Callice to experience the vibrations from the execution shed. The latter trio were joined by Jenny and Richard Fleet because it was an exciting thing to do. The clock with the skeleton was in the pub because Sir Henry had given it the pub owner.

These two strands of the story merge after a scary night in the prison and another death.  Sir Henry Merrivale will discover the method of the old murder, and announce the rather unexpected name of the murderer.

Carter Dickson is one of the pen names of John Dickson Carr, a prolific writer of mystery novels. Especially mystery novels which deal with impossible crimes. Carr intended to add some humor to the Sir Henry Merrivale books, and the battles between Sir Henry and Lady Brayle certainly do this. This book was published in 1948 and does not seem to be in print, but used copies are available.