Christie is nothing if not versatile in the style and structure of the various Poirot novels, it's like she's trying out new ways to tell the story with each novel.

This time around Poirot is involved from the very start, but very exceptionally he actually has to look very hard to even find a murder to solve and we are exposed to a rare insight into Poirots inner dialogue, including a good deal of insecurity and doubt.

In these latter novels, Poirots biggest challenge is boredom and the growing fear of being to old to solve murders, his hunt for challenging cases and the way he forces himself into the investigation is a big part of this novel.

We also get a very rare team effort between Poirot and Ariane Oliver (Christies alter ego), who's also part of the whole investigation.

The story is set in the wild sixties a decade Christie clearly viewed with some reservations, which gives place to quite a few remarks about the maladjusted (and mostly criminal) youths, that seems rather prejudiced today.