Who will be alive in the morning? Late October in the Lakes and the lives of six strangers become intertwined when they all get lost in the mist up on Scafell Pike. Amanda and Jilly, at a conference, take Sunday off for a mountain stroll; hedge-fund managers Mark and Richard are forced by conditions to ditch their plane; while illicit lovers Alex and Dawn have strayed on to the wrong road. All are drawn to the distant lights of a vast old tower set high on a crag where no one is home - though the door is not locked and a log fire burns in the grate. When mysterious Lucian steps out of the mist, he seems not to mind them sheltering there and invites them to stay on for as long as they like. But then they discover the landline is cut, the TV won't work and they can't get a mobile signal. As darker things slowly emerge, there is no escape ...