It can be tricky to explain the charms of the Golden Age locked-room mystery to the uninitiated. So many of the trappings of the genre are (let's face it) fairly absurd, and if the reader can't get over that fact, he or she is never really going to feel the magic. Which is a shame, because John Dickson Carr is FOR TEH WIN and Doctor Gideon Fell is a Creation of Genius. In a typical John Dickson Carr novel, a crime gets committed in a totally baffling way, surrounded by circumstances that just don't make sense, and a cerebral detective of some description turns up to puzzle out the logical (if contrived) explanation. The suspects, witnesses and general supporting cast tend to consist of opinionated eccentrics, no-nonsense coppers, and air-headed Wodehousian couples who have trouble understanding that reality won't obey the rules of the detective stories they've read. Although ironically, of course, it will.
John Dickson Carr wrote a large number of these locked-room mystery novels and and novellas, but The Hollow Man, also known as 'The Three Coffins', is widely regarded as his masterpiece. Much of Carr's output was 'variations on a theme'; Hollow Man feels like it's the closest he ever got to a definitive example of the genre. All the trappings are in place, including some fabulous bits of Gothic atmosphere. The backstory to the crimes - the tale of the three coffins - is as delightfully grotesque as anything Carr ever wrote, and at the other end of the scale Doctor Fell's perverse sense of humour is still spot-on. The mystery itself is, naturally, very clever, and although some of the details are bit contrived in the usual Carr way, there are some fantastically logical surprises in store which will really have you smacking yourself on forehead when you realize how obvious they should have been.
And yet... at times The Hollow Man almost feels like it's trying to hard to fit in absolutely everything that Carr thinks defines the locked-room mystery. This culminates in an extensive fourth-wall-breaking 'lecture' towards the end of the book, in which the detective Doctor Fell addresses the reader directly and methodically classifies all the clever methods by which Golden Age murderers commit their impossible crimes. It's not even a very rigorous classification - half of Carr's own books don't fit any of the patterns described, although maybe that's the point and Carr is showing off on purpose.
Either way, it jars a bit. It seems like Carr probably thought that his readers were already reconciled to a certain amount of ambient absurdity in this sort of mystery, and wouldn't mind another knowing wink. If so, he underestimated my powers of suspension of disbelief, at least, because I didn't find most of The Hollow Man anything less than completely immersive, implausible though it may be. If you've read other Carr, you'll know what to expect and The Hollow Man delivers it in spades. If you haven't read any Carr yet, you'll just have to take my word for it that he's the best kept secret of the Golden Age of Crime. Compared to Dickson Carr, Dorothy Sayers is a total chump. Buy this book or I will never forgive you.