Emily Hammond is killed in her flat by a fetishist who makes up and wigs her corpse,the slaying recalling the murders thirty years earlier by a serial killer the Shoreditch Creeper,who had connections with Emily's house. At the same time Ripley is introduced by embittered Erin Gray to creepy,'unretired' superintendent Stark, anxious to nail Luther for killing people who eluded justice and taking the law into his own hands. Stark and Gray put a wire on Ripley as he and Luther investigate the apparently ritual murder of obscene Internet troll Jared Cass. Prime suspect is Ken Barnaby, who was plagued by Cass with taunts over his dead daughter but Luther feels sorry for him,warning him of likely arrest which spurs Ken to take extreme action. Luther finds romance with Mary Day after they literally bump into each other in a traffic prang but the killer strikes again,murdering Dani Lane, who was Emily's baby-sitter in the 1980s, and her husband.