I read Agatha Christie's The Seven Dials Mystery over the last couple of days. The copy was originally my mother's, but I seemed to have taken it over at some point. I've never read it before, even though it's either been in this house or the house I was brought up in for years. (The edition came out in 1962, so the copy's probably that old). The book itself was first published in 1929, so it's fairly early in the canon, but not that early: a book with some of the same characters, The Secret of Chimneys, appeared five years earlier. (It's sometimes hard to gauge just how old some of the Christie stories now are.)
In this one (and presumably in its earlier companion piece) Christie uses a light-hearted style that's reminiscent of P G Wodehouse. She doesn't have quite the wit or wondrous use of language that Wodehouse can provide, but all in all, there are some funny moments, and some of the characters are just as daft as those in many of the Wodehouse books. This means, however, that when two of the young men are murdered quite early in the piece, there's not much sense of anything except frivolity. No one really gets very upset about the deaths.
The tone of the book is similar to some of the Christie short stories that my wife and I listened to while we were on holiday at the beginning of the year. They have two particular features: one is the humour, which isn't quite what you expect from Christie (some of her novels are quite dark), and the other is a sort of self-referencing, in which the characters often remark on how much like a story or a novel or a murder mystery the events happening to them are. In Seven Dials, Christie has various characters say that such and such a thing couldn't be happening, because that only happens in books. It's almost as if she's trying to see whether the reader will accept the absurdity of what's going on. Curiously, she gets away with it, time and again.
The plot is very involved (the section at Wyvern Abbey being perhaps the most complex) and the reader is expected to juggle a bundle of characters who apparently all have very different agendas. Some of these turn out to be red herrings, as you'd expect, and there's a good deal of double crossing of the reader on Christie's part. It's probable everything fits (there's a rather longwinded explanation section at the end) but who's going to go back and check it all out?
In general the thing fizzes along at a good pace; only towards the end is there a kind of speed bump, when things seem to go temporarily into hiatus before resuming normality again.