Durlan invasion. Vic is sent on a wild goose chase that runs him across various urban legends, including the Chupacabra, Loch Ness Monster and the Mothman. When he gets to the end, the League admits they came up with the scheme to keep him out of the way while they dealt with the invasion.
He knows, of course, and zaps Superman with a taser, revealing him and the others to be Durlans. Then the real League (whom the Durlans had put on a ship headed to the sun, but Vic saved them off-panel) burst through and the day is saved.
Also notable for being the only JLU thing I know of where anyone actually called him Vic.