The United States is a vast landscape of conspiracy theories. Stoked by the internet, the flames of fake news challenge our notions of reality on a daily basis. In fact, we’re presently experiencing a defining moment for conspiracy theories. Daniel J. Clark’s fascinating documentary Behind the Curve dares to take on what is possibly the King of All Conspiracy Theories: that the Earth is flat instead of spherical. Flat-Earth societies have been around since the mid-20th century and were on the decline—then the internet happened, and a brand new American flat-Earth movement began to coalesce. This documentary follows some of the loudest voices in the movement, proclaiming their truth through live appearances, podcasts and websites.