In the Dark Places by Peter Robinson

When a farmer's tractor is stolen and blood is found on the floor of an abandoned hangar, the police joke about how insignificant the crimes are. But soon DI Annie Cabbot is dealing with a missing person named Michael Lane, who could have a connection to the tractor and DS Winsome Jackman's bloodstains appear to be related to Michael too. With their boss, DCI Banks, in charge, the detectives soon find themselves immersed in much more serious cases.  With this latest entry in the long-running series, Robinson puts the focus on the female detectives Annie and Winsome, and lets Banks take a back seat.  It works well, along with an intriguing mystery. "In the Dark Places" will be published in August.