The hunter by Tana French

It’s a blazing summer when two men arrive in the village. They’re coming for gold. What they bring is trouble. Cal Hooper was a Chicago detective, till he moved to the West of Ireland looking for peace. He’s found it, more or less – in his relationship with local woman Lena, and the bond he’s formed with half-wild teenager Trey. So when two men turn up with a money-making scheme to find gold in the townland, Cal gets ready to do whatever it takes to protect Trey. Because one of the men is no stranger: he’s Trey’s father. But Trey doesn’t want protecting. What she wants is revenge.