I think this would be one of Christie's most enjoyable mysteries, but the romance actually gets in the way for once. Luke and Bridget are not terribly endearing, and they are never less endearing than when they are doing their lover-ing bit. However, looking past that, the set-up is quite nice, and Luke's detecting style is quite a bit different from either Poirot's or Miss Marple's, as befits an actual police detective (though retired) rather than a private investigator.
This was one of Christie's most psychologically complex books. It was a very enjoyable read, and I would recommend it to anyone who loves a challenge of solving an extremely interwoven mystery.
Oh, my, good old Agatha Christie had me stumped with this one to the very end! And I really thought I had it figured out. An entertaining mystery which opens with what Luke Fitzwilliam thinks is a "dotty old woman" entertaining him with "tall tales about a series of perfect murders" on the train to London. A very good read and true Christie all the way.