After her terrifying experience at the hands of the Watchers, Mina has escaped to a cottage on the west coast of Ireland. She obsessively researches her former captors, desperate to find any way to prolong the safety of humankind.

When Mina encounters a stranger near her home, she fears the worst - for she knows the figure is not what it seems. Soon, people she has encountered start to disappear.

Mina knows the Watchers' power is growing. She flees for her life, but when she reports her fears she finds her sanity questioned. Can she convince people that the Watchers are real, and ready to strike - or will she suffer the fate she has dreaded since she first encountered those malevolent beings?