Two women are dead It was a vicious calculated murder The killer selected his victim at Euston station, followed her home on the tube and strangled her to death in front of her child At the same time, killed in the same way, a second body is discovered at the back of King's Cross station It is a grisly coincidence that eerily echoes the murder of two other women, stabbed to death months before on the same day DI Tom Thorne sees the connection between the two and starts to investigate