Mt. Snowdon, Yr Wyddfa to the locals, is crawling with tourists in the summer months. So Constable Evans isn’t unduly alarmed when a young female hiker goes missing for a few hours. She might have taken a wrong turn or even stormed off to hide after a tiff with her boyfriend. The routine search turns more ominous, though, when the village police find an underground bunker—complete with handcuffs and chains. Now, as he copes with wedding plans and a visit from his disapproving mother, Evans has a serious investigation on his plate, searching for a link between the still-missing girl and the eerie, empty chamber. And when his own fiancée disappears, the case goes from ominous to terrifying…