Starring: Nathan Fillion, Stana Katic, Tamala Jones, Jon Huertas, Molly C. Quinn, Susan Sullivan, Seamus Dever
Continuity mistake: When Castle is freezing stuff in his apartment and Martha starts talking to Alexis about her forthcoming exam, she is either holding an iPod or a glass of wine in her right hand between shots.
Audio problem: When Demming writes "Stolen books" on the white board and says, "Killed for a fortune in stolen books, so I'll run the work crews and see if anybody has priors", his lips don't match what he's saying at all.
Trivia: Castle's Halloween costume is of Malcolm Reynolds, played by Nathan Fillion in the short-lived TV show "Firefly." Alexis asks him: "Didn't you wear that like five years ago?" Serenity, the film based on Firefly, was released 5 years before this episode aired.
Question: Before this episode, there was a Christmas episode "Secret Santa" and then there was "Significant Others" with Meredith showing up to take care of Alexis. In that episode, Beckett mentions choosing the movie Valentine's Day for a date night, causing her to lose a turn. In this episode, Castle and Beckett are celebrating their first Valentine's Day together. So, are they celebrating Valentine's Day twice? This wasn't too long after the Christmas episode and when Beckett made her movie choice, no snow was on the ground. Is this a mistake or is this really their first Valentine's Day together?
Answer: The networks are now having winter breaks. A mid season end of new episodes, when they come back after the new year, it picks up as if several months have gone by. Beckett suggested Valentine's Day as a "chick flick" to watch as she is moved in. Also some episodes are not scheduled to air in order.