A man in Washington D.C. is stepped and slashed by a masked man with a machete. SSA Andrew Mendoza of the Washington field office appears. Prentiss is right behind him with the BAU. This is the third attack within an hour, with the first victim dying. The BAU is teaming up with the FBI Washington field office. The unsub is calling 911 before the attacks, every 27 minutes. All three victims were found in areas outside of their normal routines. One man shoots another because he resembles the description of the unsub. Lewis figures out the unsub is driven by inequality. Alves determines the unsub has a partner, so it's a pair of spree killers. They are taking turns in the attacks. The attacks are meant to be statements. Prentiss lets Luke out of the office, to search for the next victim. A man with a phone starts streaming Reid and JJ working to save the fourth victim, but he dies. Luke tracks down one of the unsubs, caught with a machete in his hands, and he surrenders without a fight. The unsubs are brothers, James and Marcus Wells, whose brother Tom got stabbed to death. Marcus won't tell Prentiss what James is planning, and why they are killing every 27 minutes. That's the same time it took the ambulance to get there after he got stabbed. Prentiss thinks James is heading to Hallridge University, where Tom went to school. James takes a female student hostage. Mendoza offers himself as a hostage in exchange. Marcus slices Mendoza, then holds him hostage. Prentiss distracts him, then Mendoza trips him and Prentiss takes him down. Mendoza is rushed away by ambulance for treatment. Prentiss goes to check in on Mendoza. He invites her out on a date.