Nathan Fillion has confirmed that his character will clash with the new police captain when Castle returns.

Penny Johnson Jerald recently signed up to play Victoria Gates, who is replacing Captain Montgomery in the ABC show.

Fillion has now told Collider that Castle will begin to realise that Montgomery had motives for keeping him around.

“What we discover is that Roy Montgomery had a reason to have Castle there,” he said. “He had an interest in Beckett and felt a responsibility towards her. He knew she was haunted, knew she was tortured, and saw the effect that Castle had on her. So he had an interest in keeping Castle close.

“The new captain, not so much. She’s not invested in these cops, and certainly not Castle, the way that Montgomery was. It’s going to be much more difficult for Castle.”

Fillion also suggested that Castle will be thrown when he realises that Gates does not respond to his charm.

“Castle is accustomed to being surrounded by women,” he said. “He’s accustomed to people adoring him. He thinks pretty highly of himself, he thinks he’s pretty charming, and he’s never had a lot of trouble in that area.

“But when you have someone like our new captain who is not swayed by his charms, who does not see a use for him being around when she has plenty of good cops, you have someone who’s a thorn in Castle’s side. But Castle is not someone who takes failure to heart.”

Fillion added: “I don’t know if it’s so much about proving himself, to Castle anyway… For me, right now, it’s about, ‘Can Castle get his way?’ Castle is very accustomed to getting his way.” [Source]