The squad join forces with French Resistance members to rescue one of the Resistance members who has been captured by the Germans. They are successful in their rescue attempt but are pursued by the Germans and take cover in an abandoned mine shaft. Heavy fire from the Germans causes them to retreat further into the mine where they wage a running battle with the attacking Germans. During a pause in firing they realise that the mine is in danger of collapsing and just at that point a German tries to hit them with a grenade. He is shot but the grenade explodes bringing down the roof and trapping Allies and Germans alike. A truce is called and Lt. Hanley meets with the German Lieutenant Mauer [Skip Homeier] in the open area of the mine where they agree to a stop to fighting. But its not so easy with the Resistance wanting to take on the Germans. As they explore the mine they are fired on by an unknown assailant who turns out to be a French woman, Marianne Fraisnet [Margaret OBrien] hiding with her sick boyfriend who is a German army deserter. Jacques Patron [Michael Constantine], their Resistance member, calls her a collaborator and tells the others how a woman collaborator in his village had 6 villagers shot. One of them was his 16 year old brother. They try to dig their way out and decide to use their only two grenades to help. While they are cleaning up after that attempt, the sick German dies, and all start to believe they will also. Pfc Tommy Bishop and Pvt Wexler decide to keep digging and find they have much in common as they talk and dig. Lieutenant Mauer walks off with his pistol having decided that he would rather kill himself than suffocate as the air runs out. When Lt. Hanley goes looking for Mauer they argue over the possibility of escape and Mauer accidentally wounds Hanley in a scuffle for his pistol. While this is happening Pfc Bishop and Pvt Wexler find water dripping from the roof and realise that they have found a way out. Bishop goes looking for their Officers and arrives to find Mauer standing over Hanley and shoots him. Pvt Wexler then arrives and turns his rifle on Bishop but Hanley kills him before he can shoot Bishop. The survivors then make their way out of the cave.