I promised you my thoughts on Agatha Christie this week, so here it is, a little shorter than usual, because I've only just finished reading her, and I'm still working out what I think. This week on the water I read The Murder of Roger Ackroyd and The Mysterious Affair at Styles back to back. The puzzle in each held me for a while and then it didn't. Three bedrooms with interleading doors, locked but not always. A stain on the carpet. A chair placed at a particular angle. A view from a...