Mekia Coxis putting on her blues and joiningThe Rookiesquad to shake things up.

An official investigationultimately cleared all parties of wrongdoing.

But Cox is here to inject the series and Nolans policing with some new energy.

And watch the clip above for more.

Might her background as an undercover detective complicate things for her or make her a non-traditional T.O.

in some ways?Yeah, youve got it there.

What I really like about this character, shes got a ton of layers.

Because shes like, oh shes this badass thats coming in and shaking things up.

Harper and Bradford butt heads.

Weve seen Nolan without an anchor these first three episodes.

Hes been moving between mentors like Lopez, Grey, and Detective Armstrong (Harold Perrineau).

Hes been working with Grey, whos a little bit more grounded.

Even Bishop was definitely grounded.

She was a bad-ass in her own way, but she was more grounded than this character is.

This character has sort of lost herself, even though she is really good at her job.

What needs to be done gets done.

He happened to be in the beginning of the scene and I came in later.

John has a way of learning from any and everyone that is above him.

He admires Detective Armstrong, but then there are also things that he admires in Nyla.

He is sort of a sponge.

Because I think he really does admire both and wants to be like both in ways.

Nolan has to contend constantly with people reacting to his age and the fact that hes a rookie.

She just thinks this is something I can poke fun at, great.

I dont think it throws her in any way.

Because its going to be different than some new 20-year-old coming on to the force.

But for her, it initially might be strange, but she ends up liking it a little bit.

So far with all the series regulars, weve gotten glimpses into their love life.

So, in terms of romance, thats the only romantic relationship that she has had.

She doesnt know who she is anymore.

What was the process for coming on board like?

I found out I got the job on Tuesday, and I started working on Wednesday.

In the first fitting for a series regular role, they have to find your entire closet.

So that takes some hours.

So we had to do hair and make-up tests for all of those characters.

So that ended up taking several hours.

It was a lot in the beginning.

For example, extra long phone chargers because you always need that when youre in your trailer.

A pair of really great sunglasses that I wear all the time.

Just little things that are exactly right for you being on set every single day.

Were just very happy to have you.

I thought that was very sweet.

It immediately made me feel super comfortable.

And Ive just had a pretty awesome time on this set.

Its a wonderful cast, amazing crew.