Grace Park, Lauren German

The Hawaii Five-0 task force had a reunion of sorts in last week's season premiere, but the team won't be the same now that there's a new boss, Lt. Gov. Denning (Richard T. Jones), in charge.

"He's a little tougher than the old one, so we need to be more careful with him," Scott Caan, who plays Danny "Danno" Williams, tells TVGuide.com. On Monday's episode (10/9c, CBS) Denning demonstrates that he's not about to let Five-0 slide with their lawless methods. He assigns Homeland Security profiler Lori Weston (Lauren German) to join the team to keep them in check.

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Steve McGarrett (Alex O'Louglin) is unsurprisingly "dubious" about the newcomer. Check out his reaction upon learning the news:

The new Five-0 team doesn't have time for welcome parties or hazing rituals, however, when they get called to investigate the kidnapping of a teenage paddleboard champion.

Meanwhile, one of their own isn't aware that they have a new member. "Kono is not even around them. She doesn't even know that there's another person. She doesn't know anything," Grace Park says about her character, Kono Kalakaua, who lost her badge after being suspected of stealing money from HPD's evidence locker. "She suspects that she doesn't belong with the team, and they're all just trying to make her feel better. But eventually you have to go take care of your own business. That's what she embarks on. When Lori comes in, Kono is already out of the picture.

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"Kono has been dealing psychologically with the same situation that her cousin Chin Ho's been [in], being scandalized," she continues. "It's almost worse, like a double hit in the same extended family. It's extra embarrassing. Just before they can celebrate his clean record or his being brought back, it's kind of sullied again."

Making life more difficult for her is Internal Affairs Capt. Vince Fryer (Tom Sizemore), who is continuing his interrogation of Kono. "Fryer's hot on her tail. He's onto her, the whole investigation. He doesn't believe her. He doesn't trust her. So he's really out to sniff out what he thinks is suspect. She's got a lot to cover up and try to prove at the same time. I think the character dynamic is interesting alone." Her pal McGarrett also has some problems when he runs into Fryer. "There's tension between the two characters," O'Loughlin confirms.

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And even though Five-0 isn't Fryer's biggest fan, the same couldn't be said about the cast's opinion of Sizemore. Not only does Caan call him a "genius actor," but O'Loughlin promises, "He brings a whole new energy and a whole new level of danger and a whole new level of excitement to the show."

Here's a sneak peek of when Kono meets Fryer:

The episode "Ua Lawe Wale (Taken)" airs Monday at 10/9c on CBS.

Do you think Kono can stay with Five-0? How can she shake Fryer? Are you glad to see a new addition to Five-0?