Toks Olagundoye, the newest star of ABC's Castle is revealing that there will be "mayhem" ahead in the new season.

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Olagundoye is joining Castle for the show's upcoming eighth season, where she will play Hayley Vargas, "a quick-witted, free-spirited former Scotland Yard police officer who works as a security specialist and is not afraid to cross lines to get things done."

The actress is starting work on Castle this month, and while she can't say much on what's ahead for season 8, she did tease something on Twitter recently. A fan asked for spoilers, to which she responded:

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It was previously reported that Hayley would be spending a lot of time with Castle (Nathan Fillion) in the new season, though the extent and content of that "time" is not yet known.

Olagundoye's introduction comes as Penny Johnson Jerald is exiting the series as Captain Gates. Jerald had previously been a series regular on Castle for four seasons before getting the axe shortly after the season 7 finale.

Fans do not have to worry about other stars leaving before the new season. Fillion, Stana Katic (Beckett), Jon Huertas (Esposito), Seamus Dever (Ryan), Susan Sullivan (Martha Rodgers) and Molly Quinn (Alexis) are all signed on for season 8.

Castle season 8 premieres Monday, Sept. 21 at 10 p.m. ET/PT on ABC.