 Four men from the Hammelburg underground have been taken prisoner and Hogan and his men have been ordered to free them and smuggle them out of Germany. When they get back to camp their smuggling operation is jeopardized by a leaky water pipe which has collapsed their emergency tunnel. Soon a fountain is gushing in the camp and Hogan convinces Klink it is a healthy mineral spring full of life enriching nutrients. While the Germans are lounging in the new bath house Hogan hopes to smuggle the men out of the camp.