Where do we even begin with that season finale? Last week, Cat found out her dad was a dirty cop working for the Capellas until he was killed by Luke. This week, we saw just how far the Capellas would go to pay back Cat for her father's betrayal. Let's dive into...The Case of Cat's UnravelingThe episode starts off in Marseille, France, where Leo's ex-wife Aimee and son Nico prepare for their trip to New York. As they chat about sightseeing and reuniting with Leo, two men watch from a car and tail their cab to the airport. One of the men is on the phone with someone very interested in learning Leo's whereabouts.In New York, Leo anxiously awaits his family's arrival by vacuuming in the middle of the night while Cat buys an untraceable gun with cash. At the precinct, Capt. Baker asks Esposito if he's seen Cat lately. Her disappearance has Baker worried about what she might do, like stake out the Capella home with a gun. She's doing just that from inside her car when Gregg invites her over, but Cat dismisses him. Later that night, Gregg hears a knock at the door and assumes Cat has changed her mind. Instead, Giada enters and removes her coat, revealing she's wearing nothing but lingerie.At the French airport, the two hit men following Nico and Aimee report to their boss that the pair is flying to New York. Their boss orders them to contact their friends in the Big Apple and tell them to kill Nico, Aimee and Leo after they land. Who's the mysterious man on the phone? The person from whom Leo stole.The next morning, Gregg wakes up covered in scratches but with no recollection of the night before. He tells Giada she has to leave but when she doesn't respond, he realizes she's dead. Cat, still sitting in her car outside the Capella home, is about to make her move on Luke when Gregg texts, saying it's an emergency. At Gregg's apartment, Cat surveys the crime scene. Giada was strangled by hand and there's blood and skin tissue under her nails. Gregg swears he didn't kill her and shows Cat video messages from Giada, in which she threatens to kill herself if they don't get back together, as proof. Cat calls Monica to help.Leo and Ronnie are headed to the airport to pick up Nico and Aimee when they spy Annabella meeting up with Rhys. To get proof of their meeting, Ronnie follows them into a restaurant and takes a seat next to them so he can record their interaction. Rhys is revealed to be an American named Tommy who was paid off by Annabella. Leo immediately sends the video to Cat.Meanwhile, Baker and Esposito head to Cat's apartment, where they discover she's still obsessed with avenging her father's murder. Shortly after, Baker gets a call informing him Luke Capella has been murdered. His body is discovered in the same location where Cat's father was killed. A cop at the scene tells Baker Capella was executed and begging for his life when he died. The murder weapon is also discovered nearby and is covered in Cat's fingerprints.At Gregg's apartment, Cat watches Leo's video and realizes Annabella has been behind everything, even remembering Cat's love of British accents. When neither Gregg nor Monica believes her conspiracy theory, Cat reveals that her dad killed Tommy Capella, Annabella's grandfather, and that she served as his alibi to help him cover it up. With evidence mounting, a reluctant Baker is forced to put out an APB on Cat, which Leo and Ronnie hear in Leo's cab. After getting a call from Baker, Leo asks Ronnie to pick up Nico and Aimee at the airport so that he can go help Cat.Monica finds needle marks on Gregg's neck, proving he was injected with something. But to further prove Gregg's innocence, Monica says the cork from the wine bottle must be tested if Cat and Gregg's theory about the wine triggering his memory loss is to be believed. Cat realizes that if Annabella is targeting her loved ones then her mother is also in danger. She calls Leo to find out where Frankie is but Leo wants to know why she's wanted for murder. Cat explains that Rhys provided Annabella her fingerprints, hence why they are on the gun. Leo in turn tells Cat that her mom is on the ferry to North Williamsburg. Baker and Esposito pull up to Gregg's apartment just then, but Cat and Gregg manage to drive away.At the airport, a pair of hit men is waiting for Aimee and Nico, who are greeted by Ronnie at baggage claim. When the man on the phone is informed Leo is not with them, he instructs his accomplices to kidnap Aimee and Nico and hurt Ronnie, but keep him alive.Racing to reach her mom, Cat drives into a park with Baker and Esposito in pursuit. Leo soon catches up with them and joins their car chase, but Baker and Esposito's vehicle is sidelined when another car blocks their path. At the dock, Cat finds Annabella waiting for her. Leo is right behind Cat until he gets a phone call from Ronnie, who has been stabbed by the hit men. He tells Leo that Nico and Aimee have been kidnapped and that Leo's "old pal Henry" has come to collect.Cat and Gregg approach Annabella with guns blazing, but she warns them that there's a bomb on Cat's mother's ferry and if anything happens to her, the bomb will be detonated remotely. Annabella explains her motivation for revenge by telling Cat that her grandfather meant more to her than her father. Cat's dad worked for Annabella's grandfather for many years before killing him in cold blood to keep from being exposed as a dirty cop. Annabella also admits to killing her own uncle, Luke, to frame Cat and that Giada is her crazy cousin.Baker and Esposito break up the showdown then, aiming their guns at Cat and asking her to drop her weapon. But Cat doesn't listen until Leo reveals his family is being held for ransom and begs for Cat's help in getting them back. When Gregg and Cat put down their guns, Gregg spies a shooter and jumps in front of Cat, taking a bullet to the chest. He lays there in front of her, bleeding out, as Baker arrests Annabella. Ronnie collapses at the airport, seemingly facing the same fate as Gregg, while Leo gets a call from the kidnappers and hears a distressed Nico over the phone. In the distance, a ferry explodes.Will Gregg, Ronnie and Frankie survive? Can Cat help Leo recover his family? The season finale of Taxi Brooklyn certainly left us with plenty to think about.