Sophie Hannah's latest deals with the dark side of motherhood, mistaken identity and murder-suicide family "annihilation". It starts with a psycho babysitter apparently attempting to push a harassed mother under a bus. While this woman's involvement in the main storyline, about a murdered mother and daughter, initially seems peripheral, soon enough she is drawn in, in ever more bizarre ways, as the narrative switches between her account and a diary, ostensibly written by the dead mother, detailing her callous feelings towards her daughter (although perhaps unsurprisingly, nothing is as it seems). The story really takes off with the comic interplay between the detectives investigating the increasingly complex case, as sly digs at the cult of criminal psychologists, a bit of thwarted love interest and an unexplained scandal are all thrown in for good measure. The numerous plot twists might teeter on the edge of the incredible, but this engrossing thriller ultimately comes down on the right side of plausibility.