October, 1940. Bombs are falling on Stratford when air-raid warden Sylvia Parks sees a house with a shining light, in clear breach of the city's strict blackout rules. With no answer at the door she manages to break in, only to discover the body of a young woman, strangled to death with a stocking. For Detective Inspector John Jago, the scene brings back memories of the gruesome Soho Strangler, who murdered four women a few years ago but has never been caught - could there be a connection?