A man arrives in an empty warehouse with a rosary in hand and announces his arrival. A gun appears from the dark and fires at the man. At home, there is a family dinner where Kate and her father Jim have joined Martha and Castle. Martha has baked and just when the dinner is about to begin, Martha and Jim have a disagreement about baseball. Kate and Castle seem a little awkward and the sound of murder would be like music to them at the moment; and their phones ring. There is a murder downtown and they immediately leave. Esposito is on the scene and says that the victim is Father Joe McMurchy.
The real estate lady arrived to show the property and found the Father. He is a long way from home and his parish is uptown. The TOD is 7-10 last night and COD is 3 to the chest. The shell casings have been taken away; looks like the work of a pro. Ryan arrives and tells them at a guy named Jerry Genkins who is a bartender, says that he knows about the murder but will only talk to a detective. Kate goes to meet him. Jerry tells Kate and Castle that a guy named Leo who arrived at the bar said that he heard some gun shots and saw a man running out of the building. He gives them Leo’s address. A nun walks into the precinct. Sister Mary is ready to tell them anything they want to know. She says that she knows the murderer; Michel Dolan, a mobster. The Father and Dolan grew up together and they were friends.
They had a terrible fight outside the church. She tells them that last night he got a call around 6 and left in the middle of a mass and told her that the call was about Dolan. Kate and Castle are walking towards Leo’s and they are arguing about what happened during dinner and defending their parent’s actions. When they arrive at the door, two men arrive with guns pointed at them. They ask them to toss their phones and wallet. When they learn that Kate is a cop, they knew it was about Leo and that they should inform the boss. Leo opens the door and Kate and Castle enter the house and lock it from inside. The guys start banging the door. Kate tries to make a call but the phone is dead and all their stuff is outside. They tell Leo that the guys are after him as he opened his big mouth at the bar. Leo is freaked out.
Kate kicks open a window and they get out through that. But Kate sees that her car isn’t there and Leo is surprised that she left her car is this sort of a neighborhood. They are now stranded in a bad neighborhood. The video from the security cameras confirm the nun’s story. The call that the Father received was from a pay phone. Ryan and Esposito realize that they aren’t able to reach Kate and Castle. Ryan checks on Kate’s car and Esposito goes to Leo’s house to check what transpired over there. Kate breaks the window of a car to grab the cell phone lying inside; but the phone is password protected. The guys who are chasing them come around and they run. Esposito arrives at Leo’s house. He looks at the scene and calls Ryan telling him that they have a problem. Castle decides to break the pass code to the phone and Kate suggests that they should take the subway.
Castle disagrees but they then decide that if Castle is unable to crack the password, they would take the subway. Esposito reports to his Captain about the scene. Martha and Jim arrive at the precinct to meet Gates. They are not going anywhere till they get their kids back. Ryan tells Gates that there was some turf war in town and the only guy who is left behind is a guy named Colin Clark. Castle figures out that the passcode could be the woman’s cat’s name. Just then the owner of the phone calls and tells him that she wants her phone back as she has her pet’s pictures and all other things in it. She has GPS on the phone, so she knows where they are. Castle hangs up the phone and types LOLA (the cat’s name) in the password and bingo; they are in! But just then the owner disables the phone. Oh no!!
They then see a cab but the driver refuses to take them to the city and drives away. The guys who are chasing them spot the trio and they run. Leo has hurt his ankle pretty bad and he can’t stand. Kate finds a place to hide but they won’t be able to stay there for long as those guys would figure out where they are hiding. Gate interrogates Colin. Colin lawyers up. Ryan decides to lip read the video where the Father and Dolan were having a fight. Kate and Castle are still bickering and Leo tells them that this spite is not about their parents; it is about them. At the precinct, Martha and Jim are now cordial. Kate and Castle too iron out their differences. Castle manages to get an old radio they found in the basement, working. Leo tells them that the guys are gone as he cannot see them. Castle decides to go to a nearby restaurant to make a call. Kate stays back with Leo.
At the precinct, Ryan and Esposito tells Gates that they could not lip read the video as the cameras are too far off; but they see that after Dolan leaves, the feds arrive to meet the Father. So, Dolan must have thought that the Father would have pointed him out to the feds. Gates feels that if the feds have had their eyes on Dolan, they will know where he is. Kate is trying her hand on the radio. Castle is about to walk towards the restaurant, when a car pulls up and the guys shoves Castle into the car and Castle is now sitting face to face with Michael Dolan! Dolan is a smart chap and he knows that the best way to play poker is by calling the opponent’s bluff. He figures out where Leo and Kate are.
Gates talks to the Federal Agent and he tells them that Father was not heir informant; Dolan was as the Ftaher had convinced him to turn in evidence against the mob family in return for immunity. Dolan was in fed custody and on hearing about the Father’s death, he escaped. So, that means Dolan didn’t kill the Father. Then who did? Ryan feels the O’Rileys, who Dolan was going to testify against had motive. And that is why they are all leaving town. So, Dolan is hunting the guy who killed the priest and the O’Rileys are hunting Dolan. One of Dolan’s men enters the basement where Kate and Leo are hiding.
Leo tackles him down to the ground and Kate is shocked. He then aims the gun at her. Leo then tapes her hands. He tells her that he is an independent contractor. He killed the Father and acted as the witness as he knew that Dolan would come for him and at that time he could kill Dolan. Castle and Dolan are talking in the car and Dolan tells him that he did not kill Joe as he was his best friend. He only wants the witness. Leo takes the guy’s phone and asks Kate to get Dolan to meet them. Kate speaks to Dolan and she agrees for a trade; Castle in exchange for the witness. They decide to meet near the bridge. Both parties arrive and Leo empties his gun into Dolan’s car without giving anyone any time. But the car is empty. Dolan and Castle emerge from behind a pillar.
Castle had figured out from his conversation with Kate that something was up. And so they hid behind the pillar. Dolan now knows that Leo killed Joe and he is about to shoot him but castle stops him. Leo tells Dolan that the O’Rileys won’t leave him and that he is a dead man. The cops arrive. Dolan and Leo are arrested. Kate and Castle arrive at the precinct and are shocked to see their parents getting along really well.