In a prologue set in 1976, Don Francis, an American epidemiologist with the World Health Organization, arrives in a remote village on the banks of the Ebola River in Zaire. He encounters a mysterious illness that claims the lives of many residents and the doctors who work with them, later identified as the Ebola hemorrhagic fever. The stark images of the dying and the cremation rituals he witnesses haunt him as his career takes him toward the study of HIV/AIDS at the Centers for Disease Control and Prevention years later.
Jump to 1981, and Francis contends with a surge of unexplained deaths among gay men in major American cities due to a rare immune-system-threatening condition, pneumocystis pneumonia. He moves to Atlanta where CDC Administrator Dr. Jim Curran asks him to lead an in-depth investigation into this new immune disorder. The working conditions are poor—tight budgets, cramped spaces, outdated equipment—reflecting the Reagan era's restraint on public spending. He clashes with several segments of the medical community who have their own agendas and skepticism about his conclusions.
While examining early clues, Francis and his team encounter the gay community and witness how the disease appears to spread through sexual contact. Some individuals, like activist Bill Kraus, rally to support the investigation, while others push back against what they perceive as intrusive meddling in private lives. Kraus even puts his own relationships at risk when his partnership with Kico Govantes suffers as he helps push for change and awareness.
The scientists also face resistance from the blood industry, which fears financial losses and slows cooperative efforts to curb transmission. At the same time, a rivalry unfolds between American researchers and their French counterparts from the Pasteur Institute. The dispute intensifies over credit for identifying the virus and developing a blood test, with Dr. Robert Gallo at the center of the tensions and anger when he learns of collaborations with the French team.
By 1984, the crisis hits closer to home for Kraus when a spot on his ankle signals Kaposi's sarcoma, a marker of AIDS. He and Govantes reunite as Kraus confront his illness, while the scientific community continues to respond to the evolving knowledge of the virus. After the official announcement of the AIDS virus, Francis pushes a comprehensive plan for prevention and a potential cure, but encounters resistance from Curran, who deems the plan unaffordable and blocked by bureaucratic obstacles, and Francis is reassigned to San Francisco.
In the following years, Kraus's health declines; he passes away in early 1986. Francis remains at the CDC until 1992, when he leaves to work on an AIDS vaccine project. The film closes with a tribute sequence set to Elton John's The Last Song, featuring a montage of notable individuals affected by HIV/AIDS and reminding viewers of the human cost behind the scientific race.
