In the wake of devastating losses, Sienna Nealon has reached her breaking point. No longer content to play by the rules, she's gone rogue—hunting down the worst criminals across America with ruthless precision. But as the authorities close in and the body count rises, Sienna knows this can't last forever. When her eccentric family tracks her down with a mysterious proposition, Sienna is pulled into a web of ancient secrets that threaten to upend everything. With old allies rallying and new enemies emerging from the shadows, she'll have to confront her deepest grief and face enemies long thought dead—or risk losing what's left of her world in an epic clash that spans myths and modernity.