After a king, grieving the loss of his wife, finds himself lost in a perilous forest, he is compelled to marry a witch's daughter to secure his escape. The new queen, Greta, grows envious of the king's attention towards his children and plots her vengeance. Under the cover of darkness, she transforms six of the king's sons into swans, leaving Elisa, the sole daughter, alone. Elisa embarks on a quest to locate her brothers and discovers them dwelling in a secluded cave. Overjoyed by their reunion, she witnesses the toll of the curse on her brothers and pledges to break the spell, no matter the sacrifice.