The incredible story of Miloslav Druckmüller, an amateur solar eclipse photographer who, with his perseverance and invention, caused a global breakthrough in solar research... For scientists, the Sun is not just a glowing ball in the sky that gives us light and heat, it is a cosmic body whose turbulent processes can destroy our civilization. Investigating the mechanisms of the Sun's magnetic field is only possible during a total eclipse. But there is a catch. The eclipse lasts only a few minutes, during which everything must be recorded as best as possible and then the results processed mathematically. Although the Sun's behavior could destroy the energy grid on which we depend, his research did not move for a long time due to this problem. But then Brno's mathematics professor Miloslav Druckmüller came up with an extraordinary idea that changed everything. What was initially just a personal hobby carried out on vacation, turned into collaboration with scientists from all over the world and NASA - and also into famous visually fascinating footage. The documentary film Helios, which captures the incredible story of a Czech scientist, is at once a portrait, a popular science film, and a road movie through the American West, where watching the "Great American Eclipse" became a social phenomenon in 2017.