Graham Calder was once a soldier. He lives a quiet life now, far from people in the Scottish Highlands, ever since a terrible injury in Afghanistan. It wasn't the enemy who scarred him, though - it was his brother-in-arms, Simon Bussey. Now Bussey's back.

The Grant sisters, Claire and Emily, hope for an adventure in Scotland's forests and mountains. Neither planned on fighting for their lives as they become entangled in the soldiers' deadly feud.

Bussey assumes Calder hides away because of his injury. He's wrong. Calder lives with schizophrenia, and can, because a ghost taught him to lock the nightmares in a box inside his mind. If he opens the box and let his demons out, will the Grant sisters survive?

They might...or it might just be Calder who kills them all.