Da Capo, an imprint of Grand Central Publishing (GCP) and the Hachette Book Group announce the publication of IN MY DARKEST HOUR: A Memoir  by Dave Mustaine with Joe Layden on September 8, 2026. “ In My Darkest Hour is Dave Mustaine at his most revealing, vulnerable, and true,” stated Ben Schafer, Executive Editor, Da Capo. “With lacerating honesty and soulful reflection, he speaks to the universal human experience of facing serious illness and how it changes a person, the