Mercy Seat is a compelling story of desire, loss and regret set against the rugged coast of west Wales. Luke, a boy on the brink of manhood, drifts to a remote seaside town but can only replace his lonely childhood with responsibilities – marriage and fatherhood – for which he is perilously unprepared. The arrival of Christine, his wife's estranged sister, draws Luke into the unspoken, destructive mystery at the heart of the two women's relationship. As his understanding of himself and others begins to unravel, he must make a choice that will haunt his life forever.