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Family vacations are all about relaxing and time away from stress — unless a serial killer is after you.

Check out photos of the CSI: NY cast

Just ask CSI: NY's Danny (Carmine Giovinazzo) and Lindsay (Anna Belknap), who find their beach getaway interrupted by an escaped murderer in Wednesday's season finale (airing 10/9c on CBS).

"They've been working hard and want to take a little break with the family," Belknap tells TVGuide.com. "They find out right before they're going to leave that Shane Casey [Edward Furlong], who had been caught at the beginning of the episode, has gotten out again. It's more and more clear that their vacation is not going to go so well."

Casey's name has popped up a few times this season, starting when Danny's badge was stolen and fingerprints at the scene matched Casey's. Casey later used Danny's badge to bust out during a prison riot, and now his long-term plans are about to be revealed.

"He's going to have more than a minute to explain himself, why he feels the way he feels and what's driven him to this place," Giovinazzo says. "We have a couple really intense scenes, where he basically goes on and on about why he's doing what he's doing and why he's so angry. ... Obviously he's a psychopath and a murderer, but I feel like you have moments where you feel for him."

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Adds Belknap: "You will see the human being, which can be even more unsettling. The guy is crazy, but you get a little bit of a look into his soul."

In case the stakes aren't high enough with a fan favorite couple in danger, their baby, Lucy, will also be "a very big part" of the drama, Giovinazzo says.

"But where we leave it, we're not sure what he's trying to f---ing do. We really don't understand, we don't know. Danny's family's involved, the whole team's involved, and it really comes to a specific head in the finale," he adds.

CSI: NY's Hill Harper: We'll see how diabolical Shane Casey really is

Belknap promises the ending will have fans chatting about the cliff-hanger all summer, and Giovinazzo, whose character also figured into last season's cliff-hanger, loves the uncertainty.

"It's a really dramatic ending where somebody's going to die and you really don't know who," he says. "I'm glad I'm involved — to put me on the slab and make that what everybody's going to wonder about is exciting."

How do you think the season will end?

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