MARI HANNAH - The Insider

'It was the news they had all been dreading, confirmation of a fourth victim.'

When the body of a young woman is found by a Northumberland railway line, it's a baptism of fire for the Murder Investigation Team's newest detective duo: DCI David Stone and DS Frankie Oliver.

The case is tough by anyone's standards, but Stone is convinced that there's a leak in his team - someone is giving the killer a head start on the investigation. Until he finds out who, Stone can only trust his partner.

But Frankie is struggling with her own past. And she isn't the only one being driven by a personal vendetta. The killer is targeting these women for a reason. And his next target is close to home...