1836. Wisconsin. Catalina lives with her pa and brother in a ramshackle cabin on the edge of the wilderness. Mama died years ago, and the harsh winters have brought the family to the brink of starvation. Catalina has replaced her poet's soul with an unyielding determination to keep Pa and her brother alive, period. When Pa suddenly takes ill, Catalina tries everything to revive him. But as soon as the illness claims him, a strange man appears - a man covered in bark, leaves growing from his head and sap dripping from his eyes. Before Catalina can stop him, he scoops up her brother and disappears, leaving behind a bird with crimson wings. She can't let this man - if that's what he is - have her brother. With no idea where they've gone, she grabs Pa's knife and Mama's jorongo and follows the bird. Along the way, she finds help from a young lumberjack, who has his own reasons for hunting the Man of Sap. As their journey takes them deeper into the woods, they encounter strange beasts and tormented spirits who share secrets of the past. The more they uncover about the Man of Sap, the more they learn how deeply Catalina's fate is entwined with his, planted long ago in cursed seeds.