In 1934, a backyard auto mechanic, his dullard brother, and an M.I.T. graduate fleece the Massachusetts State Police at a Boston auto show when the trio steals a Thompson submachine gun from an exhibit. Days later, the bandits turn the weapon on hostages used as human shields, while killing two police officers during a bank heist in the sleepy suburb town of Needham. For the first time in Massachusetts history a machine gun has been used in a crime. It is yet another job during a ruthless deluge of bloodshed which leaves two more citizens dead and a pair of taxi cab drivers caged in a courtroom surrounded by a legion of vengeful witnesses on the verge of convincing a jury to sentence the friends to death by electrocution. Mired by political motivation and turmoil within an unorganized police force, tenacious detectives, known as "The Four Aces", find themselves clashing with more than just gangsters. Now, two rival crime reporters must combine wits to piece together the truth under the weight of competition between the city's mightiest newspapers. Against them are the tick of time, deficient evidence, and the indifference of cold blooded killers.