Youre not used to seeingMoonlights Alex OLoughlin looking like a serial killer with OCD.

(You prefer to remember him the way we do: either holding a Hi Slezak!

sign at 2008s New York Comic Con or shirtless.)

Criminalmindsoloughlin_l

But its only for a role.

OLoughlin guest stars on tonights episode ofCriminal Minds(CBS, 9 p.m.

ET) as what fans of the series know as the Unsub, or unidentified subject.

Im eating an apple while we talk.

That is fine, yes.Thank you.

I read it and was like, Absolutely.

Its not often that I get to play character roles.

You kinda leave drama school and you head off into a direction and thats the direction you take.

Youre either on the character actor route or the leading man route.

It was a delight for me to play a role like this.

Youarethe leading man inthe CBS pilotThree Rivers.

Its a fantastic script thats really grownup and smart and important.

It tells the story of organ transplants from three perspectives: The organ, the recipient, and theorgan?

[Laughs] It tells it from theorgansperspective.

From the recipient, the donor, and the surgical team.

I read that Andy is separated from his wife and lives in a motel near the hospital.

Is that right?Yeah, connected next to the hospital, actually.

So he can live his job even more than he usually does.

No, I told them Im happy to do whatever sex scenes they want.

Either with actors or by myself.

So theyre getting back to me on that.

That may or may not be a reason why they pick up the show.

Hes obsessed with sex.

No, were not gonna pick the show up.Moonlightfed with him.

Hes kinda all weird now.

I see three years ahead, you know what I mean?

I see the fifth season.

I see where the characters are going to go, the potential.

I loved the character.

Ive sat in on five open-heart surgeries now.

And whats Andys personality like?Hes a bit cheeky, too.

Hes like a lovable scallywag.

Youre about to start filming the movieThe Back-Up Planwith Jennifer Lopez.

Right after she does this, she bumps into this guy called Stan.

She falls in love with him.

He falls in love with her.

She tells him about the pregnancy after theyve fallen in love and he flips out.

Its a terrific little film.

Youve met Jennifer already, obviously.

Hows the chemistry?The chemistry is fine.

I think were gonna be pals.

So I think its gonna work.

I think were gonna be really good onscreen together.

Her husband is wonderful.

I met Marc and the kids, and theyre great.

Theyre a really lovely unit.

You also costar in the thrillerWhiteoutcoming out this fall.

[Kate Beckinsale plays a U.S.

Marshal in Antarctica in the graphic novel adaptation.

]I cant remember how many years ago I shot that.

I cant remember what I did in it.

[Laughs] No, thats not true.

Im looking forward to seeing that.

Theyve been cutting it forso long.

Thats Kates film though.

Essentially, I play the villain in that as well.

A rogue-ish, rugged, Australian pilot whos a bit of a smartass.

Its likeWow, what a stretch.