The Cambridge research team discovered a virus that can put the infected in a permanent killing state. This virus spreads very quickly and cannot be suppressed. After members of an animal protection organization accidentally released a group of gorillas carrying the virus in the laboratory, the prosperous London turned into a dead city in just 28 days. When the bicycle courier (Cilian Murphy) woke up one morning 28 days later, he found himself lying naked in a dilapidated hospital, surrounded by a mess, which made him suspect that he was dreaming. When night fell, he was attacked by people infected with the virus. Fortunately, he was rescued by Selena (Naomi Harris) and Mike (Noah Huntley) in a critical moment. He also learned about everything that happened in London. The only people in the city who were not infected were a very small number of London residents and some soldiers stationed outside Manchester. When the three of them struggled to find a glimmer of hope to save the future, they found that the real horror was not the virus.