Pilot Hardass Detective Caitlyn "Cat" Sullivan, a woman hell-bent on finding her father's killer, is demoted to foot patrol for reckless driving, disobeying orders, and personality conflicts. Cat arrests Marseille born taxi driver Leo Romba, a highly skilled driver with a past. Accused of being a wheelman in a bank robbery, Leo begs Cat to make a deal: in exchange for proving his innocence, he will provide her with his driving skills and taxi. The unlikely partnership grows into friendship as they investigate a series of robberies, and Leo becomes Cat's confidant in her personal investigation of her father's murder.
Brooklyn Heights Sasha Lowenthal, a famous handbag designer, asks Cat to work on the disappearance of her son Ian, an infamous socialite hell-raiser. When Cat and Leo find Ian murdered, their investigation reveals a world of high society ripe with family secrets. An internal betrayal leads to Leo's arrest by Immigrations and Customs Enforcement officers.
Cherchez Les Femmes Cat and Leo investigate the beating death of Leo's friend, a survivor of the Holocaust. Elsewhere, Cat becomes Leo's sponsor to help him with his immigration problem.
Precious Cargo A foster mother is murdered, prompting an investigation by Cat and Leo. Before long, Cat is surprised by the bond she forms with one of the foster children. The case turns personal for Leo, who misses his own son in France. Meanwhile, Cat asks to open a case into a mafia family.
Ambush Two female prisoners are killed and four escape when a prisoner-transport van is ambushed. One of the escapees is a witness to the murder of Cat's father. As Cat pursues the on-the-lam inmates, she comes closer to the truth about her father's killer.
Love Hurts Cat's buried emotions are brought to the forefront when Amanda Pearson, the wife of the Park Slope Stalker, is found murdered. The stalker case made Cat famous, and almost got her killed. When Baker asks her to take the lead, she hesitantly agrees, as long as Leo stays by her side. What they uncover is another stalker out to kill Cat.
Black Widow Three men are found dead under mysterious circumstances, but similarities in their physique and taste in watches seems to point to one murderer, a Black Widow. Leo fits the profile of the victims and agrees to go undercover as bait to catch the killer, putting his life in danger.
Deadline Brooklyn Walking the streets of Brooklyn, Cat and Leo discover a dead man in a dumpster, or at least they thought he was dead. The man was exposed to some sort of weaponized toxin and his rambling words are Apocalyptic. The NYPD goes into high terror alert as they rush to control the possibility of mass exposure. Leo's convinced it's a Zombie outbreak, but Caitlyn uncovers a terrorist plot.
Double Identity Fernanda Flores, a hard-working maid from El Salvador, is shot in the streets of Brooklyn. Cat, Leo and Frankie investigate and discover that Fernanda is actually a former cop from Venezuela who disappeared six months ago, and is in Brooklyn seeking revenge against a CIA agent who killed her parents and kidnapped her little brother.
The Longest Night A blackout puts half of Brooklyn in the dark. Cat arrests Styx, a member of the Jungle K's gang. Trying to escape, Styx kills two cops in the precinct. Everyone becomes a suspect when Cat discovers it was a planned hit and someone in the precinct gave Styx a gun. It's an intense and explosive showdown when Styx's gang shows up demanding his release and gunfire rains down on the precinct.
Frenchmen Can't Jump A motorcycle messenger was to deliver heroin to Mario Maura, suspected of drug dealing with the mafia family, when he got shot by another motorcycle driver. Mario took this job in hopes of protecting his girlfriend. Parallel to that police investigation, Leo disputes an amateur basketball tournament but he makes a shocking discovery.
Revenge Leo's son comes into town with his wife, but the trip takes a turn for the worse. Cat gets caught up in an investigation and has to prove her innocence before she can help Leo save his family. The episode ends in an unsightly disaster that prevents Cat from finding answers.