Michael C. Hall Michael C. Hall

After his wife's murder in the Season 4 finale of Dexter, Dexter Morgan starts his new season under suspicion in her death. Fortunately, he has an alibi - but it brings another set of problems: He was busy chopping up the Trinity killer when Rita died.

"The spouse is always the first person that people look to, but he does potentially have another alibi," star and executive producer Michael C. Hall said of the new season at a Comic-Con panel Thursday.

The panel included the first footage from Season 5, which opens (spoiler alert) just moments after Dexter discovers his wife dead in a tub full of blood.

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"We want to process this huge event, which is almost like a second origin story," executive producer Chip Johannessen said. "This is something he brought on himself. We don't continue the facts of Season 4 for very long, but the set of events that he brought upon himself very much permeate Season 5."

Adds Hall: "He's motivated by a desire to make amends for that even if he doesn't consciously know it. He needs to make things right, even if it feels impossible."

Rita's death will not only cause Dexter to feel guilt for the first time, but make him a single parent to baby Harrison and stepchildren Astor and Cody.

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"[The theme of] this season is not so much about Dexter's sheer body count, but that he's in a much more emotionally ragged place than he's ever been," Johannessen said. "And this thing that always calmed him and brought him peace doesn't work anymore."

Dexter will also have to deal with suspicions from his co-workers at Miami Metro (especially Quinn, judging from sneak footage of Season 5). The season will also feature a slew of guest stars including Julia Stiles, Johnny Lee Miller and Peter Weller.

"We have very different adversaries for him and pressure in ways we've never seen before. We see a new type of relationship that he's never had before, too, at the center of the season," Johannessen said, referring specifically to Stiles' character.

Johannessen said this season will definitely bring more bad guys into the mix. "We wanted to get away from the single serial killer," he says. "We're not doing a serial killer of the week thing. We just have more balls in the air."

So will Dexter's newfound sense of guilt, combined with his extra responsibilities, lead to a life without bloodshed and bodies?

"An appetite remains for killing and I think there's an inexpressible unquenchable vengeance alive in Dexter now because of the fact that he killed Trinity and allowed himself to express a sense of kinship and a sense of mercy, only to discover that the guy had murdered his wife," Hall said. "He can't bring Trinity back to life and kill him again, so he has to find other victims."

The new season of Dexter premieres on Sunday, Sept. 26 at 9/8c on Showtime.

(Additional reporting by Natalie Abrams)

Watch the Season 5 trailer below: