The invitation to spend Christmas in Angle, on the Pembrokeshire coast, is one that Lyn Ravenshaw is only too happy to accept. To escape London and the pressures of her literary agency is temptation enough, but the prospect of meeting Booker Prize nominee James Swift - conveniently in search of an agent - is the deciding factor. On holiday she encounters the disturbing Elen Vaughan, recently widowed and with an eight-month-old son whose paternity is a subject for local gossip. Elen's baby arouses painful memories of Lyn's own dead child/ and strange, haunting dreams, in which a young woman in blue repeatedly tries to hand over her child to Lyn for safekeeping.

Who is the father of Elen's baby? What is the eerie, monstrous creature of Elen's dreams that tries to ensnare her son, and what makes her so sure that Lyn has been sent to protect him? As she begins to untangle the truth behind the stories, the secret she discovers leads Lyn to an encounter with the past that will change her life forever.