As Supt Heaton deals with Ian Ellis's suicide attempt, DCI Jack Meadows reveals that, as Ian has an alibi for the murder of Elaine Putnam, he may not have killed Susan Clark or Rebecca Clayton, the crime he was imprisoned for 20 years ago. At St Hugh's, Ian rages at Heaton for robbing him of 20 years of his life, and is angry when Heaton asks for his help to catch the real killer - but agrees in order to clear his name. Heaton explains that all three women had gone to a rave the night they went missing and, as he had worked at the events, Ian gives Heaton the names of all his former colleagues, before begging Heaton to release him from prison. The team visit the workshop of electrician Phillip Dowson, who worked at all the raves, and find the same electrical wire that the women's bodies were tied up with - and their missing shoes. Phillip's wife, Emma, is brought in for questioning and is overwhelmed when Heaton suggests that Phillip was involved in the murders of Susan, Rebecca and Elaine. Emma admits that Phillip has been acting strangely for the past few months but refuses to believe he's a killer. Heaton is faced with the mammoth task of getting Emma to reveal where Phillip is - before he strikes again...
