A tense, high-concept thriller set against the pressure-cooker world of a deep-space mission, Holdout follows a principled scientist forced to confront a crisis that could change not only her own fate, but the future of humanity’s place in the universe. Blending hard science, moral urgency, and escalating suspense, Graham Moore delivers a propulsive story about survival, conviction, and the cost of telling the truth when everyone else would rather look away.