ROXANNE GREEN catches a shuttle to her first job of the day in her role as a live body Contagion for the government, used to immunize urban populations. JESSE CHO, an anti-Contagion activist, is flirting with co-worker  NICOLE when his office is breeched by Roxanne’s team. Led by Roxanne, the Contagions try to contain the workers inside the building, chasing them down. Panic ensues.

Jesse and Nicole escape, and breathe a sigh of relief only to have Nicole “downed” by “Catch and Release” workers from another vaccination team. While Nicole is inoculated inside a roving immunization van, Jesse learns that his brother has succumbed to the disease plaguing the city. Filled with doubt, he returns to his apartment and finds Contagions there. Jesse trades words with Roxanne, resisting, before final admitting that his brother has indeed suffered. Roxanne immunizes Jesse.

The next day Jesse wakes and goes back to the office. Everything is normal. He feels okay and so does Nicole. Maybe all will be alright? Six weeks pass and Jesse feels good. 100% vaccination rate is declared by the government.

Jesse and Nicole go out for lunch to celebrate but learn that the vaccination rate has suddenly plunged to 0%. The virus has mutated. A man in the deli coughs up blood and chaos returns with customers panicking and stampeding out. Once again, Jesse and Nicole are caught in a cycle of fear and illness with no easy answers.