Last to Die - Tess Gerritsen

Murder. That's what they all have in common. A high-security boarding school has been set up to provide a place of sanctuary for children whohave lost their families in violent circumstances.But even locked gates and acres of forestcannot keep out a gathering threat. Detective Jane Rizzoli and Forensic Pathologist Maura Isles find themselves locked inside the school along with the students. They are told it's for their own safety.But does the threat come from outside...or from within?