Is it just us, or could you totally tell that Detective Slaughter (Adam Baldwin) and Richard Castle (Nathan Fillion) have worked together before? We were absolutely obsessed with the former Firefly-ers spectacular on-screen chemistry and hilarious banter.

That said, below is a roundup of the best Adam/Nathan (or Slaughter/Castle, depending on how you look at it) moments from Season 4, Episode 21 “Headhunters.” Enjoy!

7. Brown Coat Exchange

Slaughter and Castle’s first meeting was awesome for many reasons. Not only did the scene include a subtle underlying Firefly reference (Nathan wore a brown coat as Captain Malcolm Reynolds, and “Browncoats” is the nickname for the Serenity fighters), but it also gave us our first glimpse of Slaughter’s selfish, scandalous nature when he tried to make off with the coat without making good on his promise to let Castle ride along.

Oh, and did we mention it also included one of the best quotes of the night? “I need a writer around like a need a case of the crabs” is classic TV, people.

6. Ground Rules

Badass Detective Slaughter had some pretty hilarious rules for his new crime fighting partner, Rick Castle. First, he told him rule no. 1 was not to use the word awesome, and later that rule no. 2 was just to stay out of his way.

Then, before the dynamic duo are about to bumrush a bar for suspects, Slaughter reveals his third rule: “Ride with me, you ride strapped” before tossing Castle a gun. 

5. Slaughter: The Love Coach?

We don’t know if we’d ever take macho man Slaughter’s relationship advice seriously, but we absolutely loved the scene where he questioned Castle about his relationship with his hot brunette coworker.

“You’re tappin' that, right?” Slaughter says of the “smokin’ hot” Beckett. Castle looks appalled, which is pretty cute. When he responds that he’s not, and they’re just friends, Slaughter says “What’s wrong with you?”

Right? We’ve been asking that for years!

4. Lonely Fighter

Slaughter sends Castle into the bar alone, and he ends up having to fight off a guy all by his lonesome — as Slaughter stands idly by, nomming on peanuts.

“Well done, Sherlock. Atta boy,” he says afterward. How annoying (but funny!).

And still, we will admit it looked kinda cool when the boys walked their suspects into the precinct all tough like. Er, besides the fact that Castle had a broken nose.

3. Castle Blasts Slaughter

Slaughter pushes Castle’s buttons to the max when he starts describing a hot redheaded intern at the morgue that has the greatest “ass.” Obvi, he’s talking about Alexis, and Castle just won’t stand for that, so he punches Slaughter square in the face.

“Relax, Sherlock,” Slaughter says, followed by, “You pack a little punch there for a writer.”

Even in times of crisis, Slaughter still has a sense of humor.


2. That Guy’s Insane

One of our favorite moments of the ep is when Castle tells Esposito that Slaughter’s insane, and before he even has time to finish his sentence, the crazed cop pops his head up at the window next to him unexpectedly. Priceless. Point proven!

1. Trunks and Doughnuts

Perhaps the best and craziest Slaughter/Castle scene was after Slaughter captures the “weak member” of Valez’s herd and locks him in the trunk. Soon after Castle realizes there’s a live body in the rear or the car, Slaughter asks Castle if he’ll testify for him at a civilian review board, where he’s being called out for excessive force complaints. 

“Such bullshit, right?” as he continues e-breaking and throwing his innocent captive ‘round the trunk.

Castle doesn’t agree at first, but then Slaughter puts the pedal to the metal and speeds off down the street, terrifying Castle into agreement.