Case of the River Dragon

A video of a boy named Bongseok is blowing up at Haedal Academy! In the viral clip, Bongseok spots something big wiggling around in the river. As he moves closer for a better look, he says an awful stench fills his nose. Then, out of nowhere someone snatches his phone . . . just as a giant dragon emerges from the river! Can the Mystery Science Detectives solve this case, or will the river dragon eat them all alive?