In the fourth installment of a five-year investigation into potential attacks on American government officials and a condition, known as Havana Syndrome, correspondent Scott Pelley reports on the intriguing case of an FBI official who says she was targeted inside the U.S., and on new information about the Pentagon's global investigation into these mysterious incidents. For the first time, sources tell 60 Minutes they have evidence that a U.S. adversary may be involved. Bill Whitaker reports from the chaotic and high-speed racetrack of “America’s original extreme sport” - Indian Relay. As horse nation tribes unite for an exciting and dangerous bareback horse race, Whitaker looks at how the sport continues to grow and offer new opportunities of pride to the next generation of Native American youth.