The Curious Cousins are off to the nation’s capital with their parents, crazy Uncle Stef and his lady friend, Ronnie O’Reilly. Their sight-seeing is complicated by an unfortunate coincidence. The World Conference of Clowns (WCC) is in town the same week to hold their national convention. The Cousins are not fond of clowns, especially Steena who thinks they’re all super-creepy.To make matters worse, there’s been a rash of scary clown sightings around Washington, D. C. for several weeks leading up to the WCC convention. The CCC gets caught up in the frenzy when they encounter the demented clowns, as Uncle Stef calls them, while touring some of our national monuments. Something’s afoot that adds up to no good. It’s up to the Curious Cousins Club to get to the bottom of this baffling mystery. The only problem is that real danger lurks beneath their horrific masks.