When he was young, Sébastien de Sainte Marie saw a picture of Sylvain Saudan, “Skier of the Impossible,” and knew what he wanted to do with his life. Today, the Swiss skier picks extreme lines that few dare to try. In a sport where one slip or misjudged turn could mean death, de Sainte Marie is cool and collected. Sound of the Void follows him as he attempts a first descent of the 55-degree north face of Gspaltenhorn in the Bernese Alps and artfully captures his almost Zen-like calm.