A virus sweeps across Southport. After contracting the virus, Mara, a new mother, and her newborn daughter Mopsy retain their consciousness and struggle to survive in the ruins. Adrian, their former superior, searches desperately for them and shields the mother‑daughter pair with his personal guarantee after their reunion. Mara unexpectedly gains the power to command infected beings, becoming a vital bridge between humans and rational infected people. The ambitious Dr. Evelyn schemes against them, while deadly black fog and black rain descend. Setting aside mutual suspicion, Mara, Adrian and their allies fight the catastrophe, protect their family, explore the hope of coexistence between humans and the infected, and strive for their shared future.
