Credit: Richard Cartwright/ABC Photo: Detective Gates Defends Castle in Castle Season 6, Episode 3: “Need to Know”

Now that we’re two episodes into Castle Season 6, we’ve gotten used to seeing Castle (Nathan Fillion) and Beckett (Stana Katic) pal around Washington D.C., but in Episode 3: “Need to Know” — airing on October 7 at 10 p.m. ET — it’s Beckett who makes the journey home and finds herself in the 12th precinct when an ‘80s television star winds up dead.

While we’re more than happy to witness a Caskett reunion in the Big Apple, Detective Gates (Penny Johnson Jerald) isn’t pleased to see the mystery writer or his muse roaming her halls.  

“Mr. Castle, what are you doing in here?” she inquires as Castle strolls past her office. “You are not NYPD and you no longer have a reason for being here. This is our murder case.”

As if on cue, Agents Beckett and McCord (Lisa Edelstein) enter, angering Gates even more.

Though we still don't know why the feds have been called in to investigate this murder, it’s safe to say that some friendly competition ensues between the guys and the gals.

Check out the full sneak peek below and see all the delicious tension for yourself.

Castle Season 6, Episode 3: “Need to Know” airs on Monday, October 7 at 10 p.m. ET on ABC.