High summer. Wimbledon. 14-year-old Lydia Kennford returns home to discover the bodies of her mother and twin sister in the family living room, while her father, Philip, lies unconscious and bleeding in an upstairs bedroom. DC Maeve Kerrigan and DI Josh Derwent begin to investigate, discounting a burglary quickly and focusing instead on Philip Kennford QC himself. There is no easy explanation for why he survived when the others were shown no mercy, and they suspect he might have staged the attack on himself after killing his wife and daughter. But Kennford is a self-possessed, intelligent man who knows criminal law inside out; proving that he's guilty will be difficult.