Castle fans will soon find out what 24 viewers learned many years ago: Penny Johnson Jerald means business.

The actress, who made such a great villain on that Fox drama's first couple seasons, will come on board season four as Captain Victoria Gates. And she won't have very much patient for a certain author who likes to act like a cop.

"She's not warm and cuddly," Seamus Deaver (Detective Kevin Ryan) tells TV Guide of his character's new boss. "So the days of us being protected, and the days of Castle being very welcome at the precinct are over."

Nathan Fillion adds that there won't be any "trust" between Castle and the new captain, who has no history with him or with Beckett.

"You have a veritable stranger - who's not an easy woman - and you have Castle, who's very accustomed to dealing with women, but usually he finds himself being adored and charming. This is a woman who will not be charmed, so it's going to very difficult for Castle."

For more season four scoop, read through our coverage of the Castle Comic-Con panel.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.