The Adventures of Young Indiana Jones: Phantom Train of Doom

Young Indiana Jones (Sean Patrick Flanery) has orders to find and destroy a German artillery gun that seems able to appear and vanish at will, leaving ruin wherever it fires. He sets out with a band of soldiers nicknamed "The Old and the Bold," men with more years than caution. Peter MacDonald sends them across the German-held veldt by wagon train and hot-air balloon, and Indy stays on the gun's trail.