The last two Inspector Banks novels were pretty poor efforts, and I thought that this, largely excellent, series had run out of steam.
Piece of my Heart, however, is one of the best Banks books of all. It is two very good stories intertwined, and the plotting is very cleverly done. As another reviewer has noted, even the denouement is entirely credible, and the two plots are brought their joint conclusion beautifully.
Inspector Chadwick is a good character, who would probably support his own series, as might Sergeant Enderby. Banks was in danger of becoming a cartoon, but this novel gives him back some humanity, and he now has a new boss to deal with, giving us some friction for another couple of runouts, I would guess.
No silly twists, no ridiculous coincidences, just a really good set of puzzles and a clever answer.