Caitlin “Cat” Sullivan is an NYPD detective working in Brooklyn. After her driving privileges are suspended, she relies on Leo Romba, a highly skilled Brooklyn cab driver from France. Leo becomes Cat’s driver and a consultant on her cases. While solving crimes with Leo, Cat is also running her own unauthorized investigation into the death of her father, an NYPD detective thought to have been executed by the Capella crime family. In doing so, she clashes with her boss, Captain Baker, and her ex-husband Gregg, who has picked up the case for the FBI.

When New York Police Headquarters is confronted with the horror of a serial murderer loose on the streets of Manhattan, two detectives (Franky G and Jeffrey De Serrano) are tasked with bringing order to the chaos. Oblivious to the danger, six students from all over the world, who now attend school together in New York, are planning a memorial to celebrate the lives of their 30 lost “brothers and sisters” who died suddenly in a tragic plane crash a year prior.