Act as a seasoned screenwriter with expertise in thriller and sci-fi genres. Develop a gripping script about [PROTAGONIST], a [UNIQUE PROFESSION] who discovers a [DEADLY VIRUS] with catastrophic potential. The story unfolds in [SETTING], where [PROTAGONIST] must race against time to stop the virus from spreading globally. Include key elements like [A MYSTERIOUS ANTAGONIST], [A HIGH-STAKES COUNTDOWN], and [A PERSONAL SACRIFICE]. Ensure the plot has unexpected twists, emotional depth, and a climactic resolution. The tone should balance tension and hope, with dialogue that reflects the urgency and humanity of the situation. Provide a detailed outline for Acts 1-3, including character arcs and pivotal scenes.