For sheer originality and ingenuity this story may be reckoned one of the best tales since Gaboriau. Seldom does a detective story end with so total a surprise, which nevertheless, seems logical and natural. For the many who delight in following the intricacies of crime and the avenging hand of Justice, this book has rare charms.
For the problem is this: we know by what way the assassin gained admission,--he entered by the door and hid himself under the bed, awaiting Mademoiselle Stangerson. But how did he leave? How did he escape? If no trap, no secret door, no hiding place, no opening of any sort is found; if the examination of the walls--even to the demolition of the pavilion--does not reveal any passage practicable--not only for a human being, but for any being whatsoever--if the ceiling shows no crack, if the floor hides no underground passage, one must really believe in the Devil, as Daddy Jacques says!'"
And the anonymous writer in the "Matin" added in this article --which I have selected as the most interesting of all those that were published on the subject of this affair--that the examining magistrate appeared to place a peculiar significance to the last sentence: "One must really believe in the Devil, as Jacques says."
The article concluded with these lines: "We wanted to know what Daddy Jacques meant by the cry
Nicely put together and clever mystery.
I have read the story two years ago. I remember it being interesting and intriguing in most of its parts. However, I wasn't greatly convinced with the to be villain disclosed at the end. There were fallacies that weakened the reasoning, which were notable especially that the story was really challenging in most of its parts. Also, the story was pretty lengthly for the conviction provided at the end.