Jane survived the plague that killed humanity. Grief-stricken after her parents' deaths, she starts searching for survivors, and eventually meets Sam, a man determined to build a community and find any other survivors. They start a radio show and make their way to Brisbane, which they've advertised as a meeting spot.
On the way, Jane's Crohn's disease flares up, and she's forced to reveal it to Sam. In turn, Sam shares that he had orchitis as a teenager, leaving him infertile. Once they reach Brisbane, they find a nurse with multiple sclerosis, Judith, who hypothesizes only those with autoimmune diseases were immune to the plague.
Jane, an electrical engineer, helps Judith preserve frozen fertilised embryos, ensuring the human race's survival. They head to the meeting spot, where a dozen other survivors are waiting.
