Based on Norse/Scandanavian mythology, this movie traces the exploits of Lemminkainen as he woos the fair Anniky and battles the evil witch Loukhy. Loukhy kidnaps Anniky to compel her father to build for her a Sampo, a magical device that creates salt, grain, and gold. When Lemminkainen tries (and fails) to recover the Sampo, Loukhy steals the sun, plunging the world into frozen darkness.

Young Lemminkainen goes logging in the country of Kalevala and falls in love with the beautiful Anniky. Anniky's brother Ilmarinen, a blacksmith who possesses magic powers, is happy to hear of Anniky's new love. Five elders ask Ilmarinen to forge for the people of Kalevala the "sampo," a magic mill that produces grain, salt, and gold. Ilmarinen possesses the necessary skill, but the witch Loukhy, the Queen of Pokhiola [Pohjola], has stolen the blacksmith's fire to forge the sampo for herself. Loukhy learns from one of her sorcerers that Ilmarinen alone can construct the sampo, and she sends the sorcerer with her magic cloak to kidnap Anniky in hopes of luring Lemminkainen and Ilmarinen to Pokhiola to rescue Anniky. The plan works, and Loukhy sets tasks for them both in exchange for Anniky's release: Lemminkainen bare-handed must plow a field infested with deadly snakes, while Ilmarinen is to forge the sampo. Each succeeds at his task, and Anniky is set free. Lemminkainen returns to Pokhiola after the three have begun the journey homeward and destroys the sampo, taking with him a fragment that remains. Loukhy vengefully seizes the sun, causing Kalevala to be covered with snow and ice. The Kalevalans attack Pokhiola, but the battle is a stalemate until the Kalevalan army lay down their weapons and take up the sacred harps. The sound of their playing mesmerizes the Pokhiolans, and Loukhy is frozen [or turned to stone]. The sun shines again, and all Kalevala rejoices.