President Donald Trump’s Fourth of July blowout celebration will host military flyovers, tanks, parades, and a grand speech by the president on the National Mall.

It also sports something a bit stranger. At the Trump International Hotel in Washington, D.C., some supporters of the president are sporting T-shirts and masks bearing the face of John F. Kennedy Jr. One unidentified woman told Daily Beast reporter Will Sommer that “it would be wonderful” if JFK Jr. reveals himself today during Trump’s festivities:

You would be forgiven for being confused, as JFK Jr. famously died in a plane crash 20 years ago. But these Trump supporters are believers in QAnon, a vast, world-spanning conspiracy theory that argues, among other things, that Trump is secretly working to root out a giant child sex-trafficking operation led by Democrats. The movement gets its name from the fact that it started with anonymous online message board posts by someone claiming to be a government whistleblower with “Q” level security clearance.

Specifically, QAnon supporters believe that JFK Jr. faked his death, for unclear reasons, and that he will reveal himself to the world today as part of his efforts to help Trump take down the pedophiles. Some even believe that he will replace Mike Pence as Trump’s running mate in 2020.

QAnon’s bizarre ideas have occasionally leaked into mainstream consciousness. Former sitcom star Roseanne Barr promoted the theory in 2018, and a Broward County SWAT officer was demoted after posing for a photo-op with Pence bearing a QAnon patch on his uniform.