May 5, 1945. Hitler has been dead for five days. The war in Europe is almost over. In a castle in the Austrian Alps, American soldiers, German soldiers, and a group of elderly French prisoners grab rifles and get ready to fight the SS. Together. The castle was called Schloss Itter. The Nazis had turned it into a prison for very important people. Not ordinary prisoners. Trophies. Inside were two former prime ministers of France, Paul Reynaud and Édouard Daladier. Two of France's top generals, Maxime Weygand and Maurice Gamelin. A famous tennis champion, Jean Borotra. And the older sister of Charles de Gaulle. As the Reich collapsed in early May, the SS guards panicked and ran. The prisoners suddenly found themselves in charge of a castle, with weapons left behind, and a serious problem. Waffen-SS units were still roaming the area. Fanatics who would gladly kill them all. They needed help. Fast. One of the castle's prisoners, a Yugoslav handyman, slipped out on a bicycle to find the Americans. Separately, a German army officer named Major Josef Gangl also went looking for them. Gangl was a Wehrmacht officer who had turned against the Nazis and was secretly working with the Austrian resistance. He wanted to protect the prisoners too. He found an American tank commander named Captain Jack Lee. Lee was 27, tough, cigar chewing, and willing to do something insane. With a single Sherman tank and a handful of American soldiers, he drove up into the mountains alongside Gangl and a few of his German troops. They reached the castle on May 4. The French prisoners were not exactly thrilled to see a tiny rescue force. They had expected an army. Instead they got a few Americans, a few Germans, and one tank. The next morning, the SS attacked. Somewhere between 100 and 150 Waffen-SS troops hit the castle with machine guns, mortars, and anti-tank weapons. The defenders fought back from the walls and windows. Americans and Germans side by side. The French prisoners refused to hide. Some of them, including Reynaud, picked up weapons and joined in. The Sherman tank was knocked out. The defenders were running out of ammunition. It looked like the castle would fall. Then Jean Borotra, the tennis star, volunteered to make a run for it. He jumped the wall, slipped past the SS, and sprinted through the countryside to find American reinforcements. He found them. And he insisted on coming back with them to finish the fight. During the battle, Major Gangl saw Paul Reynaud exposed to gunfire and moved to pull him to safety. A sniper shot Gangl dead. He had survived the whole war as a German soldier, only to die defending French prisoners from the SS in its final days. That afternoon, the American relief force arrived and broke the attack. The SS were scattered and captured. The prisoners were saved. Jack Lee received the Distinguished Service Cross. In Austria, Josef Gangl is remembered as a hero, and a street is named after him. It is believed to be the only battle of the war where American and German soldiers fought together on the same side.