In Rick Riordan’s Magnus Chase and the Gods of Asgard, Magnus’s magical sword is named Jack.
Jack is a supernatural weapon with a personality and the ability to act independently. Magnus Chase acquires the sword during the events of The Sword of Summer, the first novel in Riordan’s trilogy. Although Jack is a weapon, the story treats the sword as a distinct character, giving it a voice, preferences, and comic interactions with Magnus and his companions.
The trilogy draws heavily on Norse mythology while placing its action in modern Boston and other contemporary locations. Magnus is the son of Frey, a Norse god associated with fertility, prosperity, sunshine, and peace. Readers sometimes confuse Jack with Gram, the legendary sword connected with Sigurd in the Völsung tradition, or with Riptide, Percy Jackson’s sword from another Riordan series. Those weapons belong to different mythological and fictional settings.