The ancient engers knew it as a theoretical entity, one so remotely implausible that the idea only survived in an obscure verse. How could an ages-old poem give rise to the reality of the days of the Cold Angel, days that threaten the realm's very future? And why does a woman's determination to do right by her sister put her at the heart of a mystery, one that threatens to destroy the only love that sister has ever known? Someone's lost memories lead her to a strange meeting with a man in an even stranger tower, one that pricked star holes in the sky until but a few days before. What of it now, though, and its keeper's determination to put things right at all costs? How is she to deal with the painful dilemma he draws her towards - when she's asked to weigh the love of her sister against a duty to save the realm?