I heard this twice on CD while travelling from Dunedin to Christchurch and back, in 2013. When I say 'heard it twice' I mean that the first time I heard about the first 60 pages, and then didn't hear any more, and then on a second trip, heard about 90 pages, and still didn't hear any more. So rather than trying to listen to the rest - I'm not good at just sitting listening to CDs unless I'm lying in bed sick - I bought a copy of the book, started it yesterday and finished it today. It's immensely readable, often very funny, and has a wonderfully complex plot.
There's a strong theme of the difficulties of old age - people with Alzheimer's, or trying to live on their own without family - and also the horror that many young people have for the idea of growing old. The story begins with the deaths of three old men, in fact; two of them may be accidents, the third appears to be the result of an attack. Nothing is quite like it seems, and the further the story goes, the more our original views about the deaths and their aftermaths are altered. There are some wonderfully innocent people, and some surprisingly devious ones. There are some that appear suspicious and aren't, and some that appear to be all above board - and aren't. Hill holds out attention right to the end, even though we think we've got to grips with what's going on at an earlier point.
There are an endless number of lines that could be quoted (one character, Mrs Spillings, is almost Dickensian in her speeches), but Hill reserves some of his best lines for the taciturn, and ugly, policemen, Wield (a regular in the series of books).
'Back door,' said Wield. 'Glass panel broken. Key in lock. Hand through. Open. Easy.'
Sergeant Wield was in fine telegraphic style. He also seemed to have been practising not moving his lips, so that the words came out of his slant and ugly face like a ritual chant through a primitive devil-mask.
or
Wield looked at the new acquisition and raised his eyebrows, producing an effect not unlike the vernal shifting of some Arctic landscape as the sun sets an ice-bound river flowing once more through a waste of snows.
I've read some other Dalziel and Pascoe, but I think this remains my favourite.
Update 1st November 2015: Listened to this again while travelling. I remains one of Hill's best, I think.