In less than 20 years, the Internet revolution has had a much deeper impact than all the other media on human behavior, affecting our way of thinking. Opinions and journalism are all put on the same level, without hierarchy or reserve. The Internet has thus become an unprecedented springboard for "conspiracy". Inspired by Gérald Bronner's bestselling book, 'The Democracy of the Gullible', the film looks at cognitive biases, at the natural predisposition of our brains for nonsense, and how conspiracy myths gain the spirit of our contemporaries. In this context, does knowledge still have a chance in the face of belief?