The Insider.com

Few shows returning this fall featured as dramatic a cliffhanger as Dexter since Debra walked in on Dexter dispatching The Doomsday Killer, Travis Marshall. And as you can see from this new behind-the-scenes sneak peek, that was only the beginning.

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TRAILER - Dexter Season 7

"This show is always at its best, and most potent, when Dexter is in hot water – and the water's really as hot as it's ever been now," star Michael C. Hall says. "This is the season I'm most excited about," Jennifer Carpenter adds.

And it's easy to see why as the sorta spoilery clip reveals how far Deb goes after learning of her brother's double dealings. Unfortunately for Dex, this extra scrutiny only makes his Dark Passenger flare up more often, compounding an already tricky situation.

PHOTO - Dexter Welcomes Back a Familiar Face

But there is a silver lining, according to executive producer Scott Buck: "It's not just Debra who gets to ask all the questions, it's us who get to hear all the answers." Something Michael, a six-time Emmy nominee, is looking very much forward to. "Everything from here until the end will be fraught with a fundamental tension now that this cat is out of the bag."

Dexter premieres September 30 at 9 p.m. on Showtime.