The film tells how a trip to South America inspired Che Guevara's new worldview and caused revolutionary enthusiasm to sprout in his heart. Guevara (Gail Garcia Benard Garc í a Bernal) was 23 years old, high-spirited and hesitant, a medical student. He was so curious about the outside world that he and his friend Albert went on a long journey to Latin America. They got on the motorcycle and set off at full speed, but the motorcycle was soon scrapped. But this did not affect the young man's passion at all, and the two hitchhiked to complete the rest of the journey. Passing through the ruins of ancient civilization in Latin America and shuttling among all kinds of people in various countries, they began to feel the truth of society and the suffering of life. When they went deep into the leprosy area of the Amazon, they were deeply shocked by what they saw and heard. Che Guevara began to think about the grand and esoteric proposition: human, social, economic, civilization, the definition of human suffering, happiness.