Events will pick-up six months after the season 3 finale, meaning Dexter and Rita will have had their baby!

According to executive-producer Sarab Colleton, "this season, we're going to deal with: can a serial killer juggle a personal life, work, and his 'dark passenger'? In other words, can Dexter have it all? Which is something all of us grapple with every day of our lives. So we're taking something that is a very human dilemma and putting it through the prism of Dexter's special needs."

The season will also feature another major new cast member who will "cross paths with Dexter in a major, dramatic way. He will illuminate a lot about Dexter's life and force him to make some tough choices." A rumour is circling that the producers want to cast someone similar to Jeff Daniels. What's Jeff Daniels up to? He has this audition nailed!

And, as set-up in season 3, Dexter's sister Debra "... in her need to know her father more, is going to get closer and closer to figuring out who Dexter's mother was and her relationship with her father." But, Colleton insists that Dex would never kill his sister if she discovers his extracurriuclar activities, adding: "that is inconceivable to me. Deb and Dexter are the best brother-and-sister team ever."

Отсюда - http://danowen.blogspot.com/2009/04/dexter-season-4-details.html