Lovely Sorcha is the seventh child and only daughter of Lord Colum of Sevenwaters. Bereft of a mother, she is comforted by her six brothers who love and protect her. Sorcha is the light in their lives, they are determined that she know only contentment. But Sorcha's joy is shattered when her father is bewitched by his new wife, an evil enchantress who binds her brothers with a terrible spell, a spell which only Sorcha can lift-by staying silent.

Eighteen-year-old Liobhan is a powerful singer and an expert whistle player. Her brother has a voice to melt the hardest heart, and is a rare talent on the harp. But Liobhan's burning ambition is to join the elite warrior band on Swan Island. She and her brother train there to compete for places, and find themselves joining a mission while still candidates. Their unusual blend of skills makes them ideal for this particular job, which requires going undercover as traveling minstrels. For Swan Island trains both warriors and spies.

Hulde is a queen’s daughter and lives in a palace. But her life is lonely. Growing up atop the glass mountain, she knows only her violent and autocratic mother and a household of terrified servants. Then a white bear named Rune comes to visit, and Hulde learns what kindness is. But the queen has a plan for Hulde. When she turns 16, she will wed the most beautiful man in all the world. Hulde has never met her intended husband, and her mother refuses to explain the arrangement.

In exchange for help escaping her long and wrongful imprisonment, embittered magical healer Blackthorn has vowed to set aside her bid for vengeance against the man who destroyed all that she once held dear. Followed by a former prison mate, a silent hulk of a man named Grim, she travels north to Dalriada. There she'll live on the fringe of a mysterious forest, duty bound for seven years to assist anyone who asks for her help. Oran, crown prince of Dalriada, has waited anxiously for the arrival of his future bride, Lady Flidais.

Whistling Tor is a place of secrets: a mysterious, wooded hill housing the crumbling fortress belonging to Anluan - a chieftain whose name is spoken throughout the region in tones of revulsion and bitterness. A curse lies over Anluan's family and his people, and the woods themselves hold a perilous force whose every whisper threatens doom. Then the young scribe Caitrin appears in Anluan's garden, admiring the rare plant known as heart's blood. Retained to sort through entangled family documents, Caitrin brings about unexpected changes.