When a prominent politician is murdered, the Department finds itself under intense pressure from the city government to explain what happened. However, the squeaky-clean politician had another side he had kept carefully hidden from the public.
Castle Just out of curiosity, what are you wearing right now?
Beckett: What kind of name is Nikki Heat?
Castle: It's a cop name.
Beckett: It's a stripper name.
Castle: Well, I told you she was kind of slutty.
Lanie: Fun? Trust me, girl
Castle: Guess who got a date with a prostitute.
"You're Supposed to Be My Friend" - 1990s
"If I Don't" (Radio Edit) - Amp Fiddler featuring Corinne Bailey Rae
Was filmed as episode 4, but aired as episode 3, though on Season 1 DVD it's listed as the fourth episode.
Castle's ringtone when his mother calls is Richard Wagner's "The Ride of the Valkyries" (which, for film buffs, evokes 1979's 'Apocalypse Now').
Montgomery states that he has a three-year-old son.
The unnamed NYPD Officer is called "Scott" by Ryan. In "A Deadly Affair", the same policeman is called "L.T." by Castle (L.T. is the actor's first name).
In The Mistress Always Spanks Twice, Beckett's call to Lady Irena's House of Pain mirrors the call in this episode that Castle makes to VIP Liaisons to arrange a date with a prostitute.
Nesbit's clumsiness in returning the blackmail money to Laurie isn't as foolish as it appears. The real mistake was withdrawing the money in the first place, which meant that eventually the blackmail would have turned up in their financials. If the money had been left with Jeff's body, investigators would have immediately ruled out robbery and realized that blackmail was involved. Laurie's mistake was in not hiding the money; had Beckett's search warrant not turned up the cash, there would have been no hard evidence against her.
After Castle and Beckett meet with Nesbit to discuss the photos, an establishing shot of the precinct clearly shows the building as the 9th Precinct.
↑This is a reference to Star Trek: the Next Generation. Captain Picard would regularly mention this when having to leave the bridge and handing over command to Commander Riker, his second in command, or Number One.