Fourth feature instalment in the Gallic action/comedy series created by Luc Besson. A notorious Belgian crook (Jean-Luc Couchard), facing extradition to Africa, is left in the care of the Marseilles police department for a day. However, the foxy felon manages to hoodwink bumbling policeman Emilien (Frederic Diefenthal) into believing that he's actually just a humble Belgian embassy employee, caught up in a fiendish trap set by the criminal mastermind ...