The Siamese Twin Mystery was the seventh of the Ellery Queen novels and was published in 1933. Like The Egyptian Cross Mystery (the fifth in the series) a year earlier it shows signs of moving not only into more fantastic territory but even into the realms of the grotesque.
It certainly features one of the most extreme examples of the popular mystery novel mechanism of having a group of suspects isolated geographically and cut off from contact with the outside world. In this case the suspects, along with Ellery Queen and his father Inspector Richard Queen, are trapped in a mountain-top house by a raging forest fire. Needless to say the fire cuts the telephone lines. The fire not only isolates this small group of people, it threatens to annihilate them! There are occasions when a fictional detective finds himself in a race against time, with some disastrous consequence likely to follow if he does not solve the mystery within a specified time frame. This novel takes that a step further - Ellery has to solve the mystery before he and everybody else in the house become nothing but charred cinders!
Of course we don’t really expect this fate to eventuate (given that we know that Ellery went on to be the hero of several dozen further novels) but Ellery certainly believes that death is imminent. Dr Johnson once remarked, “Depend upon it, Sir, when a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully.” In this instance knowing he is likely to be burnt to a crisp in the next day or so doesn’t initially seem to have had the desired effect on Ellery’s mind. He makes several serious errors during the course of his investigation. On the other hand as death seems to be becoming more and more imminent he does seem to be finally inspired to find the correct solution.
Ellery’s mistakes may indicate that the authors were becoming bored with the notion of infallible amateur detectives, although Inspector Queen makes some even more serious errors (one of them very unfortunate indeed).
The murder victim in The Siamese Twin Mystery is brilliant surgeon Dr John Xavier who is engaged in some medical research of a rather grotesque nature. In fact from the moment that he and his father are forced to take shelter from the fire in Dr Xavier’s house Ellery has an uneasy feeling about the strange household dwelling on the mountain-top.
You may be wondering if the title is to be taken literally. This story does in fact involve actual siamese twins. While siamese twins have featured as characters in various horror stories this is to my knowledge the only occasion on which they feature in a detective story.
The Siamese Twin Mystery is plotted with the skill one expects from the authors and it includes one particularly clever twist that serves to lead us astray, as it leads Ellery astray. It also features a very elaborate variation on the theme of dying messages left by murder victims.
Oddly enough this novel apparently originally included the famous Challenge to the Reader that was such a feature of the early Ellery Queen mysteries but for some reason it appears that it was deleted from most of the paperback editions.
The Siamese Twin Mystery has everything that a fan of the golden age puzzle-plot detective story could possibly ask for. Highly recommended.