Georg Elser, a carpenter from the village of Königsbronn in southern Germany, came to see that Hitler was going to destroy Germany - so in 1939 he resolved to assassinate him, acting completely alone. The home-made bomb he placed in the Bürgerbräukeller beer cellar in Munich, where Hitler was making a speech, exploded as planned... but Hitler had unexpectedly left the building 13 minutes earlier. 13 minutes that could have changed the history of the world. Who was this simple man who recognised at such an early stage that Hitler would cause a devastating war - a man who acted while others went along with the Nazis or kept silent?