On June 4th, 2004, a sixty-three-ton bulldozer, fortified with steel and concrete, systematically destroyed numerous businesses and homes in the small mountain town of Granby, Colorado. The rampage lasted over two hours and resulted in more than eight million dollars in damage. State and local police were incapable of even slowing the machine. Though it was armed with three high-powered firearms, no one but the driver was killed. His name was Marvin Heemeyer. 'Tread' explores the polarising perspectives on this man, his motives, and what drove him to the breaking point.