Both Nathan Fillion (Castle) and Marc Blucas (Jeremy) are alumni of Joss Whedon shows. Blucas was a regular on Buffy the Vampire Slayer for several years while Fillion had a short, but evil, stint on Buffy's last season. He was also the lead in Firefly and played Captain Hammer in Whedon's Dr. Horrible's Sing-Along Blog.
Beckett: He's got asthma. He's allergic to cats. He reads.
Ryan: And he's good at math and he can't draw. Put it together. He's your average maths athlete with a lot of crap in his pockets.
Ryan: CSU's re-swept the scene, twice, no sign of our fifth bullet.
Castle: I'm telling you, ice bullet.
Esposito: Nah Bro, an ice bullet would still make a bullet-hole.
Ryan: You mean ice-hole.
Castle: What did you just call me?
Original International Airdates:
Canada: December 09.2009 on A Channel
Australia: February 21, 2010 on Channel 7
Slovakia: November 2, 2010 on JOJ
Germany: November 19, 2010 on Kabel Eins
United Kingdom: December 1, 2010 on Alibi
Finland: January 2, 2011 on Nelonen
Czech Republic: February 9, 2011 on Prima
Castle: Stephen King wrote stories about bloodthirsty cars and sold millions of copies. I figure, why be limited by logic?
Castle is of course referring to King's 1983 horror novel Christine, which was made into a film the very same year.