"The Brothers Lionheart" is a children's fantasy novel written by Swedish author Astrid Lindgren. The story follows two brothers, Karl and Jonatan Lionheart, who embark on a magical adventure after their deaths. They find themselves in the enchanting land of Nangijala, where they encounter various characters and face challenges that test their bravery and bond. The novel explores themes of love, sacrifice, and the importance of family. It highlights the brothers' journey as they fight against the evil Tornado and strive to protect their new home. The book is celebrated for its imaginative storytelling and emotional depth, making it a beloved classic.