Except for her (British) award-winning first mystery, The Spoilt Kill, and for the fact that a body is found in the first chapter here and identified in the last, it would be difficult to categorize this in that genre. For in between, it is the story of three couples and an outsider, involved with a Natural Science Foundation near a desolate estuary; like milkweed in a mild breeze, the story sheers here and there and you're never quite sure just where it will settle down. This too can be tantalizing, even if it doesn't altogether satisfy.