The time is 1860, and cholera is beginning to spread throughout France's chicken population. Louis Pasteur and his assistant, Emile Roux, collect samples and deduce that disease can be transmitted through air. They then draw blood from the chickens and see an unidentified germ in the specimens. While Pasteur and Roux work with the samples of blood, Pasteur has a debilitating stroke. From his bed, he expresses his determination to live, and continues to work with Roux by writing him notes. He tells Roux to inject the chickens with the contaminated blood. The chickens die. When Pasteur finally comes back to the laboratory, they discover the blood has altered from time. When they inject this blood into the chickens again, the cholera germs are killed.They have created a vaccination for the chickens. Meanwhile, sheep begin to die from anthrax. Even though other scientists mock Pasteur's findings, they agree to let him experiment on 25 sheep...