It's February 14th, 1929 - In a Chicago garage during the height of Prohibition, a group of gangsters is mowed down by Tommy Guns. It will be known as the St. Valentine's Day Massacre and its violence shocks the nation, eventually leading to the end of the nationwide ban on booze. But how did this historic hit really happen? Theo Wilson retraces the steps, from the first day of Prohibition, to the rise and secret rules of the speakeasies, to a flower shop hit and the bloody beer wars between the rival forces of Chicago's North and South sides led by ruthless gangsters George "Bugs" Moran and the FBI's "most wanted" Al Capone.