While investigating the death of an Irish mobster, Beckett and Castle uncover a local turf war that may be connected to both a late-night infomercial guru and an international drug smuggling operation. But the case turns agonizingly personal when evidence emerges that the killer they're chasing may have had a hand in Beckett's mother's murder.   

original airdate-- January 18, 2010                     rating-9.50  million

Songs: Theme Song: "Keep Hope Alive" by The Crystal Method

1. "We All Go Down As One" by Bosshouse. 
2. "Chip" by The Real McKenzies. 
3. "The End" by Pearl Jam.
4. Theme song:Castle Whistle Theme by Robert Duncan"

Goof--When the Captain hands Beckett his flask, from behind she unscrews the cap and lifts it to her mouth. We then cut to a front-on shot of Beckett and she lifts it to her mouth a second time.

• When Beckett and Castle are talking about the failed sting on Rathborne, Beckett's hand jumps back and forth from gripping her coffee mug by the handle in the close ups to the bottom in the wide shots.
• When Castle asks Trucho how he burned his hand, Trucho places the ice pack to his eye twice between shots.
• In the scene where Castle and Kate are being told that the victim's SIM card is broken and the last two digits of the phone number are missing, Castle says that they have 99 possibilities, which mathematically is wrong. Obviously the writer didn't count the combination 00. The correct number of possibilities is 100.