Singing to the Dead (Anderson & Costello #2) by Caro Ramsay

It is the run-up to Christmas when two seven-year-old boys are abducted from the streets of Glasgow. For DI Colin Anderson the case is especially disturbing because the boys look so much like his own young son, Peter.

When a simple house fire turns into a full-scale murder investigation, and with cold and flu season taking many officers off the street, the force is stretched to breaking point. DS Costello's hunch is that the crimes are connected, and a killer is ingeniously hiding his trail. As the squad struggles to work both cases, for DI Anderson the nightmare is about to get terrifyingly close to home.