A day that begins like any other, but history is forever changed after the finish line at the Boston Marathon is bombed in 2013. After the attack, the country is thrown into a sense of urgency as the Boston Police Department conducts a city-wide manhunt to uncover the terrorists behind it. Patriots Day delves into the stories of Boston Police Commissioner Ed Davis (John Goodman) and Police Department Sergeant Tommy Saunders (Mark Wahlberg) whose courage and strength help to bring justice and peace to Boston and America after being shaken by the attack. Through their sacrifice, they help to unite Americans in becoming stronger than ever before.