In the museum Martin stands watch over the past. He has travelled a long way from his brutal childhood in the Loyalist heartlands of Belfast and built a life he never imagined he would have - a devoted wife, Alison, two children, Rachel and Tom, a respectable job.

But the happiness he has found feels brittle. Rachel's academic success is launching her out of her proud father's orbit. Tom, eclipsed by his sister, has withdrawn into a fantasy world. Martin's gratitude to Alison is a gulf between them. He feels unworthy of his wife, his life, his luck.

Returning home one night to find police cars waiting, Martin feels his sins must have finally caught up with him. But their news is wholly unexpected, a senseless tragedy. And in the face of this devastating trauma, which tears his fragile family apart, Martin finds the violence of the past is not gone but merely dormant; its call must be answered at last.