A deadly pandemic begins its spread after Beth Emhoff returns to Minneapolis from a business trip in Hong Kong. Within days, she collapses and dies, and the rapidly mutating virus claims her son's life as well. Her husband, Mitch, appears to be immune but is quarantined as the government and healthcare community struggle to understand and contain the outbreak. As the disease spreads globally, society begins to break down. People panic, communities disintegrate, and misinformation runs rampant, exacerbating the crisis. Public health officials, researchers, and the Centers for Disease Control and Prevention (CDC) scramble to track the source of the virus and develop a vaccine, facing challenges of time, a terrified public, and their own personal stakes in the emergency.

Parallel to the medical community's efforts, the epidemic's societal impact unfolds, exploring themes of trust, information, and survival in a crisis. A freelance journalist champions conspiracy theories and unproven cures, profiting from the public's desperation and fear, which adds to the chaos and hampers the efforts of scientists and public health professionals. The race against time to find a cure and the economic and political pressures surrounding the crisis illustrate the complex interplay between science, government, and media in the face of a global pandemic. Efforts to trace the origins of the virus reveal a stark and unsettling connection to our interconnected global ecosystem, emphasizing the fragility of human societies in the face of such invisible and deadly threats.