Dave Johnson prays in church for a sign and is then shot through a stained glass window. Dave told his wife Wendy, he was a great novelist and that he wrote under the pseudonym PJ Moffett, a recluse and one of Rick’s literary heroes. Rick contact’s Dave’s widow and takes her on as a client in order to work the case and impress Beckett.
Martha visits with Beckett at the 12th. She asks what’s going on. Beckett says it’s complicated. Martha points out that so were Castle’s two divorces. Kate says they aren’t divorcing. Martha hugs Kate and encourages her to be honest with her husband. That he’s a rare man whom she can always count on.
Dave Johnson told a mob guy he was interviewing for research that he was actually Jimmy “Two Guns” O’Malley who ratted on the Irish mob. The mob sent assassin Billy O’Rourke to kill him but Billy realized that Dave wasn’t Jimmy. Castle tracks down Billy before Ryan and Esposito get there and the two get chummy over lunch. Turns out Dave was a pathological liar who worked as a janitor at city hall and hacked into their system where he found a $10 million slush fund taking money away from social services. He told the priest at his church.
Beckett decides to ask Castle for help to find out who in the city offices would have the access to form such a slush fund. With the help of the priest, they set up the Mayor’s Deputy Chief, Steven Reed and let him know that Dave had proof that he hid in the church. Reed steals the thumb drive and they catch him with it on his laptop.
Reed confesses to the slush fund but swears he didn’t kill Dave and he has an alibi. As Castle, Beckett, Ryan and Esposito go over the possible suspects they realize that Dave also lied to his wife of eight months about being a famous novelist. Turns out, she is the killer.
Stressing out over money, Ryan lies to Esposito about there being no more spots available for the Sergeants exam. There was just one spot available and Ryan took it. Espo is angry and Ryan tries to apologize and give him the spot. Then Beckett mentions that as Captain, she can pull strings and get them both in.
Castle hires Ryan to keep him in the loop on investigations and the working of the 12th for $500 a week.
Beckett learns CSU that every batch of heroin has a unique signature. They still have some of Vulcan Simmons’ drugs in evidence. She has them tested.
Castle brings Beckett coffee with a heart made in the foam. She says she can never quite make it right, even though he taught her how. He confesses that he left out his secret ingredient so she would always need him. She tells him to keep the secret for her. Beckett confesses that she didn’t like Castle’s favorite PJ Moffett book. That when he asked her to read it they were first dating and she didn’t want to disappoint him but she’s sorry she lied.