Castle's Kate Beckett could be be the best cop in New York City, but she may not be the best cop in the world.

On Monday's episode (10/9c, ABC), Beckett (Stana Katic) and Castle (Nathan Fillion) investigate a mysterious murder that leads them to Inspector Zhang (gust starLinda Park), a competitive, high-powered detective from Hong Kong who has information about the victim. And, as you can see in the exclusive sneak peek above, it doesn't take long for Beckett to get a little jealous — of both Zhang's professional skills and her adorable family.

Mega Buzz: Is a baby on the way on Castle?

"Did you know that she was the youngest officer to become chief inspector?" Beckett says, at first trying to downplay her envy. "She has cleared more murders than anyone in Hong Kong PD history. ... She's just like me. Only better."

But is she really? After all, once Beckett digs a little deeper into the case, she learns that neither the victim nor Inspector Zhang are what they seem to be.

Castle airs Mondays at 10/9c on ABC.