Hidden / Emma Kavanagh.

A gripping psychological thriller by a former police psychologist. Perfect for fans of Nicci French, Tana French and S. J. Watson. When Charlie's old schoolfriend is found dead at the side of the road, the police are convinced it's an accident -- but Charlie isn't so sure. The police aren't interested in hearing her theories. A gunman is at large, stalking the halls of a local hospital. No one knows who he is, or why he is there, and the best men in the force have been tasked to stop him. Among them is Aden, still troubled by his role in the shooting of a schoolboy, determined to do the right thing. For hospital psychologist Imogen, weighed down by troubles of her own, the presence of the gunman seems to have little to do with her, but she couldn't be more wrong. As the three seek answers, time is ticking down, and no one knows who the predator's target will be. Which means they are all in danger.