A classic in detective fiction and thrillers, the four are wel drawn, developed and individual characters. I first enjoyed this on audio - if you can find it do yourself a favour. THe london portrayed resonates with the touch of realism missing from say Sherlock Holmes, the police are sympathetic characters, unusual for the times. A powerful book, well developed and it kept me guessinf to the end, with some clever twists, will they or wont they manage it ?