Kamil Holán is currently one of the best Czech motorcycle racers on natural circuits. Although his material capabilities and background are far from the level of the world's factory riders, he is able to compete with them on the world's toughest road-racing tracks such as the Isle of Man. This unique documentary tells the story of a man from an ordinary background who has fallen for the passion of speed and made it his life. Flat six marks the moment when a motorcycle reaches its limit and goes into sixth gear at top speed. Does it mean success to get on a motorcycle and go all out? A look into the everyday life of an extreme racer reveals the power of unexpected conditions of success. Can we understand what a top athlete gains by putting his life on the line and what pushing the limits requires and leads to?