When is a double-edged sword not just a double-edged sword? When it’s a magic, floating, disco-loving, talking sword that can transform into a white runestone pendant. But the Sword of Summer—aka Sumarbrander, or Jack, as the former blade of Frey prefers to be called—is more than a sentient weapon. He’s a loyal companion to Magnus Chase, ready to swoop up a giantess’s nose, slice through a mob of angry dwarves, and show the way with his light-up runes if it will help save the day. The one drawback? The moment Magnus takes hold of Jack’s leather-wrapped handle, he feels the effort the sword exerted. While Jack and Magnus have a good thing going now, they both know it will come to an end someday . . . for Sumarbrander is destined to be wielded by Surt come Ragnarok.