The US election campaign is full of talk about the pandemic, the Supreme Court and police reform. But millions of Americans are tuning into an entirely different conversation. "Saying it out loud, it just sounds crazy," says 24-year-old Jade Flury, reading out a recent text conversation she had with one of her friends. She's talking to me on a video call while sitting at her kitchen table with the air conditioner on full blast, hiding away from the autumn heat in Houston, Texas. Jade's friend has been taken in by Instagram videos about QAnon - an unfounded conspiracy theory that says Donald Trump is fighting a secret war against a deep state of satanic paedophiles in government, business and the media. Despite her best efforts to counter false claims about "Democratic Party elites" running a child-trafficking ring, she's had to give up. "He definitely feels like a 'sex ring' is still a thing," she says, "and asks why no reporters are putting as much effort into finding some underlying truth to this stuff as they are into trying to discredit it." The truth is that reporters have looked into it. While the sprawling mess that is QAnon sucks in a few morsels of fact, its core is fiction, with no evidence to substantiate it. It was born on extreme message boards such as 4chan and 8chan - probably as a joke or prank - and rapidly spread among some of the president's most devoted followers.