After the billboard event wraps up, I hitch a ride with some of the group to a Crowne Plaza near the Denver airport. There I find Sargent sitting in the hotel restaurant with other movement stars and a few admiring fans. Sargent is scheduled to present the Flattys video awards at the end of the conference. He wears a black T-shirt and a black cap, like a Silicon Valley entrepreneur. I listen as he chats with an engineer named Bob Knodel, who is on the board of a group called FECORE that runs experiments aimed at proving Earth is a plane, like beaming lasers across large bodies of water in an effort to show a lack of curvature. "We're literally in a battle for humanity," Knodel says. "That may sound grandiose, but that's what it comes down to. And that's why flat Earth is so heavily ridiculed."