The Red Widow Murders by Carter Dickson

"Do you believe that a room can kill?' This is the question which Sir George Anstruther, the director of the British Museum, asked his friend Dr. Michael Tairlaine.  Four people had died mysteriously in a room over a period of one hundred years. Each had gone into the room alone and within two hours, they had died.

Then Sir George invited Tairlaine to take part in an experiment which was to be held in order to determine if the room in question was still deadly. Tairlaine was to arrive at certain spot the following evening, and if approached, was requested to do whatever the person told him  to do.

So on a foggy evening,  Tairlaine followed instructions. He was invited into a house by a butler, and was welcomed by Lord Michael Mantling, the owner of the house. The evening's activities were then explained to him.  The room which had been come to be called the Red Widow room had finally been closed off and instructions had been given by Lord Mantling's father that no one was supposed to enter the room until the house was torn down.  Lord Mantling had sold the house and land to a company who planned to tear it down and build apartment houses. Tonight was the final test of the murderous nature of the room.

A group had been gathered in the house, and a cards were to be drawn to determine who would spend two hours in the room . The group would consist of Lord Mantling, his brother Guy, his aunt Isobel, and her protege Mr. Ralph Bender. Also participating would be Mr. Ravelle who was descendant of the maker of the furniture for the room,  and Robert Carstairs who was a long time friend of Lord Mantling.  There were two witnesses who would not participate in the card drawing. They were Dr. Tairlaine and Sir Henry Merrivale who was quite an expert on the subject of mysterious poisons and equally mysterious rooms. They would be joined a little later by Judith Mantling, the sister of Michael and Guy, and her fiance, Dr. Eugene Arnold.

The person who had drawn the high card entered the room. The others waited outside the door, and called out to him every fifteen minutes. They received a reply at every interval except for the last. When no reply was heard, they entered the room and found him dead. Probably he died from a mysterious poison.

Sir Henry Merrivale would learn the whole history of the Red Widow room which went all the way back to the French Revolution from Guy Mantling. HM's investigation would lead to a final solution of the crimes for another murder would occur before the puzzle was solved.

This book was published in 1935 by John Dickson Carr under the pen name of Carter Dickson. Carr is the master of the locked room mystery. I found this book to be quite enjoyable both because of the solution of the crime and because it is very atmospheric with quite a bit of fog and rain.