Credit: Richard Cartwright/ABC Photo: Beckett and Castle Smirk in Castle Season 6, Episode 3, “Need to Know”

Now that Castle (Nathan Fillion) received the antidote and is completely free of deadly toxins, he’s able to go back to doing what he loves most: solving crimes! In Castle Season 6, Episode 3, “Need to Know,” Castle and the 12th precinct crew investigate the murder of a former child star.

But instead of Castle venturing out to D.C., Beckett (Stana Katic) and McCord (Lisa Edelstein) come to him for once when the case takes a strange turn. As we told you last week, when the ladies arrive in NYC, there’s a bit of a friendly competition between the two sexes.

“This is our case now,” McCord declares in the sneak peek below.

Perpetuating the rivalry, Beckett tells her beau, “You’re not going to Castle me on this one.”

Check out the full promo below and share your thoughts!

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