It's the one time of the year when the witch known as Cailleach hunts the children of the village - so Saoirse, a brave and reckless young girl, decides this is the perfect opportunity to defy her father and discover the secrets of the witch's tower! But when the Cailleach captures Saoirse and her brother Brahm, their lives are forever changed in ways they never expected. Now, Saoirse will have to save everyone she loves by discovering the truth about the mysterious mark on her shoulder - and embracing her secret magical powers!