Beckett is eating a lot during this episode. Stana Katic mentioned this was not because it was in the script, but simply because she was hungry. Andrew Marlowe then commented that it is difficult when Katic eats during shooting, because it is hard to combine scenes when one time Beckett is eating something and the other time she is not. He also told Katic that 'Jack Bauer does not eat or go to the loo', to which Katic responded she was not Jack Bauer, and that she was on vacation and she was going to eat. Katic guest starred in 3 episodes of "24" season 5 in 2006.
Castle and Beckett agreed 'Caskett' was a nice nickname for them, especially because of the connection of caskets with murder. Castle fans have been using this nickname for Castle and Beckett since the first season.
During discussion by Castle and Beckett of their own couple nickname (like Brangelina for Brad Pitt and Angelina Jolie), one of the variants was "Kate-ick" which is very close to real surname of Stana Katic. However, this option was rejected by both characters.
After arriving in the Hamptons, as Castle leads her to his pool, Beckett reveals that she "forgot" her bathing suit. In "Castle: A Deadly Game (2010)", Castle invites her on his and Alexis' annual Memorial Day trip and, in the course of their conversation, comments "If you are not comfortable in a swimsuit, you could just skinny dip".
Upon seeing Castle's house in the Hamptons, Beckett jokingly asks if he's rich, to which he replies he's "not James Patterson rich". Patterson, who appeared earlier in the series as one of Castle's poker buddies, is one of the most successful mystery novelists of all time; the two series for which he is best known are Alex Cross and the Women's Murder Club. In 2007, his books were checked out of UK libraries more than any other author, and that year, one out of every fifteen hardcover novels sold was a Patterson title.
The trivia item below may give away important plot points.
An amusing irony in the episode is that, with all of Caskett's efforts to keep their relationship a secret from the precinct, it was ultimately discovered because of their efforts to keep it a secret from the precinct.