This book is as if John Dickson Carr was at a party, and challenged the other guests with the idea that they could throw out four concepts - no matter how weird and disparate - and he could use all of them in one of his nutty books. And in the case of The Crooked Hinge, several drunk or high sycophants yelled out: "the Titanic!", "identity swap!", "robot!", and "hinge!!!". And so - that night - Carr didn't need to go home and throw darts at his plot-idea dart-board, and hit spaces marked hinge, robot, identity-swap, and Titanic, as he obviously had done in the past (but with results like "Mad Hatter", "Tower of London", "lost Poe manuscript", and "Fake News").
This is the first John Dickson Carr novel - from any of his series - that did not get between 4 and 5 stars out of 5 from me, simply because it never quite seemed to gel. There's also one major bit of trickery - the whole thing sort of rides on it - that I thought was shlocky and not as inspired as, apparently, I was supposed to think it was. Sure, there were hints and clues pointing at it, that I missed and that it was fun to have rounded up and shown to me, but this major underpinning of the book's trick does not seem to measure up to expectations.
There is some brilliance to enjoy; there's a big twist towards the end that makes the last hundred pages rather exciting and shocking. Everything looks to be a certain way, and then that rug under the reader's brain gets yanked hard. And this leads to reveal of the murderer whom, of course, I did not guess. Nor did I guess motive, or intricacy involved in committing the crime. There is a lot here that compares favorably to The Hollow Man, The Mad Hatter Mystery, even The Corpse In The Waxworks, and on down the line. But - this is a "you'll know it when you see it" situation - maybe more like "you'll know if it rankles you, when it gets revealed". If it does rankle you - that that - it may, as in my case, affect your entire outlook on the novel. I finish this point by saying that old saying "this one proves that even disappointing Carr is leagues better than much of the best from other authors". It's certainly a great Halloween-month read; it's creepy and tense, and clearly features a very sinister villain behind it all. It's work a look, and should satisfy bigger fans than me. It depends what you like at the bottom of a Mystery.