12 years ago, John Raglan was the lead investigator in the murder of Kate Beckett's mom. Today, he's a dying man who wants to come clean about his past indiscretions. He tells Beckett to meet him at coffee shop. No cops. So, she brings Castle. Raglan is about to reveal important details about his old case when…BANG! A bullet shatters the restaurant window striking the retired cop in the chest. Moments later, Raglan is dead.
After Beckett convinces Captain Montgomery to head the investigation, she offers to drop Castle back home. He responds, "Not a chance." Raglan's old academy buddy, Gary McCallister, points Beckett toward a drug dealer named Vulcan Simmons, who had Raglan in his back pocket. Beckett's mom led a community group that tried to shut down the drug trade in Vulcan's old stomping grounds. Perhaps the dealer ordered a hit and had Raglan cover up the crime.
Vulcan Simmons is one evil dude who taunts Beckett to the point where she bashes his head into the interrogation room mirror. Montgomery kicks her off the case. Esposito and Ryan are now running point on Raglan's homicide. They don't want the assignment out of loyalty to Beckett, but they have no choice. As for Castle, Montgomery doesn't want him playing Nancy Drew. He's off the case, too.
A worried Martha tells her son that it's time he was honest with himself about what he does. Castle says, "It's not about the books anymore." That's why he continues to help Beckett work the case of her mom's murder. Beckett reveals the details of her unofficial investigation. Not even boyfriend Josh knows about it. Only Castle.
Through some fancy detective work, Ryan and Esposito are able ID the shooter. They lift a fingerprint off the arm of the woman whose keycard he stole in order to access the building he used to set up shop. The sniper is Hal Lockwood. He has no criminal record, but anti-anxiety pills are found in his apartment. Snipers use them to slow down their heart rate when they shoot. One other thing, Lockwood has been tailing Beckett.
Beckett wants Castle to stay away from her for his own safety. No way. Castle realizes there was once a mafia club in the alley where Beckett's mother was killed. An undercover FBI agent was also murdered in the area. A mob enforcer named Joe Pulgatti took the rap. The arresting officer was John Raglin.
Pulgatti tells Beckett that the FBI agent's murder wasn't a hit. It was an attempted abduction gone south. Professional kidnappers were snatching up members of all five mafia families back then. Beckett's mom answered a letter from Pulgatti and promised to look into his case. Then she was murdered. Pulgatti warns, "There's nothing more dangerous out there that a killer with a badge."
Beckett tells the team that Raglin and at least two other cops were kidnapping mobsters for ransom. The cops knew that if the Pulgatti case got reopened, they'd all be exposed. A hit was ordered on all those involved, including Beckett's mother.
Raglin's old pal Gary McCallister was also involved in the mafia kidnappings, but swears someone else ordered the hits. This guy is afraid of someone and it's not a cop. A street dealer points Ryan and Esposito to a woman named Jolene who lives in Brooklyn. Two women fit the description. Castle and Beckett find one of them dead.
Ryan and Esposito are ambushed while investigating the second Jolene. The sniper, Hal Lockwood, wants to find out what the cops know about him and his employer. If they talk, he'll kill them quickly. Otherwise, he'll torture them. This guy Lockwood better brace himself for a long night because there's no way either of these two cops are talking. Ever.
Castle and Beckett track down Lockwood's location and assume the role drunken lovers to distract the lookout. When it appears as though the thug isn't buying their act, Castle plants a long, passionate kiss on Beckett. The sensual smooch is awesome on a variety of levels, one of which is allowing Beckett the opportunity to knockout the thug. Castle says, "That was amazing." And we get the feeling he's not referring to Beckett's takedown.
BANG! BANG! BANG! There's a shootout inside the building where Ryan and Esposito are being held. Beckett takes down one gunman, but Lockwood has her eyed up in his rifle scope. Castle jumps him from behind before he can get off a clean shot. Beckett knows that Hal Lockwood is just a cover name. She vows to find out who this guy really is and who hired him as their assassin. She'll never stop searching for the truth, not until she finds out who had her mother murdered.