
Chase and August are eyewitnesses to a young man who throws a Molotov cocktail into a car right outside the gym. The perpetrator gets killed in the ensuing pursuit, but they find out that the car was registered to Carlos Altamarino, a known drug dealer. Chase is visited by an old college friend, now a CIA agent, who gives Chase a mysterious gold key for safekeeping and reveals that Carlos' operation has shifted power to a brother, a cousin, or perhaps even Carlos himself using an alias. The new boss carries the name Charlie Altamirano. Chase's friend is killed later, and the detectives work to figure out just what exactly is going on.
Detectives August Brooks and Chase McDonald meet when August and several officers are being overwhelmed by criminals in an explosive shootout. Chase arrives in his Porche and immediately neautralizes the situation with a grenade launcher. Moments later, August discovers that Chase is his new partner, and they are immediately assigned the case to track down a bomber - nicknamed the Daybomber - who has set off a series of explosions in his quest to warn people of the advances of technology.
Chase and August are at August's gym, where they are volunteering their time to help keep kids off the street and out of gangs. In the boxing ring is Andre, a young fighter determined to stay away from gang violence. But when word comes in that Andre's brother has been shot and killed by a rival gang, Andre swears to avenge his brother's death. Chase and August try to persuade him to let the police handle it, but Andre slips from their grasp in pursuit of the killer. The incident also brings back memories for Chase, who is struggling with unresolved guilt over his former partner's murder by a gang youth.