Nicci French's novels are unusual in that they are not only extremely clever, psychologically astute thrillers, but they are also strong, atmospheric stories about contemporary women's lives. This one is about Astrid, a bicycle courier in London, who starts to worry when she realises someone is deliberately killing people she knows - either to scare her or to implicate her, she thinks. Like French's other novels, this one feels horribly, chillingly plausible - you can actually imagine it happening to you, or someone you know. The structure of this book, without wanting to give anything away, is very clever and surprising - almost a little shocking, even, but it certainly works. The best thing about French's novels, though, is that the voice and atmosphere are absolutely unique and recognisable as 'Nicci French World', and linger in your mind long after you've finished reading. French's crime novels also have a refreshingly humane feel to them - the writer(s), one senses, have a real faith in human nature, so that the books are always uplifting, despite the murders they contain. The villains aren't frothing-at-the-mouth psychos, they're flawed, damaged people that it's hard not to identify with to a certain extent, whatever they've done. Last but not least, this novel, like French's entire oeuvre, is absolutely gripping and impossible to put down, and leaves you desperately keen to get your hands on the next one.