My head snapped toward the sound, the world slowing to a crawl as I turned. I saw it all unfolding as if through thick glass—Caleb, sprinting toward Emily, his face twisted with panic. I didn’t even realize when they had gotten separated. Emily’s eyes were wide with horror, her hand flying up in a futile attempt to ward off the mercenary’s sword as it arced through the air, aiming to end her life.

A surge of something ancient and powerful rushed through my veins, a force that ...