After her brother Nuka and mother Zira's deaths, Vitani has formed an expert Lion Guard made up of former Outsiders. But one day, Tazama reports of Kasi hearing a strange, unearthly voice-and she's heard it as well! As Vitani races to find the truth, her mind whirls, and she must decide: can she face this never-before-seen threat? Or will her grief succumb her?