If we learned anything from last week's NCIS, it's that Jethro Gibbs doesn't exactly play well with others.

Gibbs (Mark Harmon) went several rounds with Agent E.J. Barrett (Sarah Jane Morris) as the two jockeyed for the lead on the Port-to-Port serial killer case. Expect more of the same when the rest of Barrett's team — played by NUMB3RS star Alimi Ballard and NFL player Matthew Willig — show up in Tuesday's episode. But it won't just be Gibbs who is on edge.

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"I think everybody's fur stands up a little bit in the beginning," Pauley Perrette tells "Abby always wants to protect her team and doesn't like change."Ballard, who plays Agent Layne Gavin, agrees that tensions initially run high, but once Barrett's team is officially put in charge of the P2P Killer, the two teams may actually begin to jell. "It's not one big cozy family when you have somebody playing on your playground," Ballard says with a laugh. "So, disagreements are bound to come up. ... But the purpose of both of those teams is to solve crimes. And when you really stay true to that, the collaboration factor happens."There has to be a point [where] people have to say, 'Put the hatchets away,'" Ballard continues. "You can get back to being the Hatfields and McCoys soon enough, but for the sake of righting a wrong ... you have to work together. You have to play nice. I think wiser, cooler heads do prevail."

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That may be because, like Gibbs' team, the new guys are a very close-knit unit as well. "They are definitely tight and loyal on our side. You see it immediately," Ballard says. "You put your life in these guys' hands and vice versa. There is a [level of comfort] about it."Speaking specifically about his character, Ballard says Agent Gavin is sometimes his own worst enemy. "He's professional; he loves his job," he says. "One of the things that I like most about him is that he is a smartass and he can't help it sometimes. He shouldn't chime in, but there he is saying something. He's always got a couple of wisecracks."That sounds a lot like Anthony DiNozzo (Michael Weatherly), doesn't it? Ballard, who previously worked with Weatherly on the ABC soap opera Loving as well as Dark Angel, says the similarity is no accident.

See photos of the NCIS cast

"When they told me that I got this job, I said, 'I have to have the opportunity to mess with Michael Weatherly,'" Ballard says. "I love him; he was at my engagement when I proposed to my wife. I don't want to say for certain [that Gavin messes with DiNozzo], but the gods can be very kind."They'll need those moments of levity to help them deal with the Port-to-Port Killer's increasing body count. "Whenever you have a serial killer, someone's going down," Perrette says.Adds Ballard: "This is the highest terror level that you can imagine. It is completely volatile. It works that people are on edge; it works for the audience not to know who's going to stick around and who's going to go. It's unnerving. ... You will be uncomfortable, but you will be extremely entertained.  If you are a fan of this show, it's going to make you nervous. You are not going to know which way the bullets are flying."
airs Tuesday at 8/7c on CBS.Watch our video interview with Perrette below: