In the world of Terre, the descendants of the winter god Boreas, the Saints of Noël, protected the Source of Yule — an entity incarnating solace, renewal, and rapture. The ensuing bloodline were champions of goodwill and peace; their annual signature celebration known as Conveyance across the lands.

Boreas' soul resided in the principal Saint, Nicholas Kringle I, and every son and grandson that succeeded him to the throne was known as the Saint of Cheer, or "Santa Claus" — Conveyance's icon, and a heart full of light.

But with every trace of light, there is darkness.

Eve Alcazar grew up without a smile. Curiosity as to why leads to an adventure she had never anticipated. Tasked to intercept winter demon Krampus' quest for the Source of Yule, Eve makes a perilous journey across the nation of Polaris with her cousin, Nick, and best friend, Desiree. But to succeed, she must accept her identity as both the once-concealed granddaughter of the current Saint of Cheer... and the muse of the King of Misery himself.