There's someone new in Rick Castle's life.

The best-selling mystery novelist will reportedly be dealing with a new detective next season, Hayley Shipton. Described as irreverent, fast-thinking and very independent, the new investigator will be played by "Neighbors" star, Toks Olagundoye.

"Castle's" Executive Producer, Alexi Hawley, talked to EW about the show's new character and says that Olagundoye's "dynamic, fun character" is "a voice that the show doesn't have."

Hawley says that she will offer Castle [Nathan Fillion] a different experience. Up to this point, the writer has always investigated cases and done things procedurally, the way the police would. But Shipton seems to be more open to trying new things and has a penchant for not following the rules — but only to an extent.

"She's a little easier than Adam Baldwin [was] on him, but there's definitely an energy about her which is a lot of fun," Hawley explains.

Shipton will also serve another purpose and one that would have a far-reaching effect on Castle's life – that of a mentor to his daughter, Alexis (Molly Quinn). According to some reports, it would appear that Shipton will have a significant impact on Alexis as she moves from a child to an adult.

Hawley admits that the producers and writers have liked the idea of Shipton being a "mentor to Alexis in a way that Beckett [Stana Katic] has been." A make-over for Alexis appears to be on the horizon as well, which includes "a more mature haircut and possibly her first sexual relationship with a new boyfriend" as the series tries to show an Alexis who's all grown-up.

"She's been playing the child for seven seasons and now she's 21 years old. She's a grown up," Hawley said. "This year, she's going to be more sophisticated."

This would also mean that the father-daughter relationship would change as well since Castle's little girl is not little anymore.

"Castle" season eight is set to return on Sept. 21 on ABC.