Warning: If you haven't finished watching the third season of "The Walking Dead," there are spoilers ahead.

Sure, we're all excited about that just-announced spinoff series, but let's not forget: The fourth season of the original adaptation of Robert Kirkman's comic book series is right around the corner. A little rundown of what we know so far about "The Walking Dead," Season 4:

1. "Twilight" star Christian Serratos will play a new character in Season 4: Rosita Espinosa, a tough, 20-something woman. Rosita is a character in the comic series, where she and two friends, Abraham and Eugene, meet up with Rick and his crew at Hershel's farm. Rosita, who is likely to be introduced later in the season, will also probably be introduced at the same time as Abraham and Eugene.

2. Another new Season 4 character also originated in the comic series: Bob Stookey, a former Army medic who'll be played by "The Wire" alum Larry Gilliard Jr. Bob is said to be traumatized by his past, both before and after the zombie apocalypse, and joins the prison survivors after he meets up with Daryl early in the season. Trivia: In the comics, Bob is a 50-something Caucasian man, while in the TV series, he's at least a decade younger and African American.

3. Actress Alanna Masterson is another Season 4 cast addition, playing a new survivor who will make her debut around midseason, Deadline reports. Little is known about the character officially, though it's said she'll be a recurring character this season, with the possibility of becoming a regular cast member in Season 5. Masterson, who's appeared on "The Young and the Restless" and "Grey's Anatomy," and is the sister of actors Danny, Christopher, and Jordan Masterson, may be playing Tara Chalmers, according to fan speculation. Tara, introduced in the "Walking Dead" novel "Rise of the Governor," is a member of a traveling family band.

4. In addition to the new cast members, three recurring cast members from Season 3 have been promoted to the main cast: Chad Coleman (another alum from "The Wire") as Tyreese; Sonequa Martin-Green as Sasha, Tyreese's sister; and Emily Kinney as Hershel's younger daughter, Beth.

5. One of the great reveals in AMC's Season 4 preview video: Hershel (Scott Wilson) appears to have an artificial leg, complete with boot, instead of the crutches he used to maneuver around the prison in Season 3.

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6. Hershel also sets up and maintains a garden, giving the prison dwellers fresh food options.

7. Those garden veggies are necessary in the new season, as the prison is lot more heavily populated since the survivors who fled Woodbury took up residence with Rick (Andrew Lincoln) and company at the end of Season 3.

8. And about the new community ... fans wondered why Rick moved the Woodbury group to the prison instead of moving his group to Woodbury, with its seemingly nicer accommodations. Lincoln told San Diego Comic Con fans that the answer will be revealed in Season 4.

9. Also important to note about the joining together of prison dwellers and Woodburyans: Not everyone is going to get along. In fact, there's going to be some major head butting, and some new alliances that form from the merging of the two factions.

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10. The season premiere episode is titled "30 Days Without an Accident," which might suggest a good month-long stretch with no deaths ... but also might signal that the 30-day-long stretch comes to an abrupt end.

11. Season 4 will consist of 16 episodes divided into two halves. The first eight episodes begin airing on Oct. 13, and the final eight premiere in February 2014.

12. In Season 4, we'll find perpetual leader Rick eschewing many of his leadership duties in order to spend more time with his children ... especially young Carl (Chandler Riggs), whose disturbing, killer behavior at the end of Season 3 has apparently shaken Rick into focusing on his daddy duties.

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13. David Morrissey initially signed on to play the Governor for just one season, but he will return as the eye-patched villain in Season 4. And it should come as no surprise that though he fled the conflict with Rick and his prison posse at the end of Season 3, the Governor has not used his time away to become a kindler, gentler psychopath. Nope, he's still one angry, bitter dude. "[Season 4 is] about how he deals and comes to terms with the man he is and what he's capable of and which side he's going to fall on," Morrissey told the Hollywood Reporter. "That's the choice he has to make."

14. Season 4 will be shepherded by Scott Gimple, the third showrunner in "Walking Dead" history, following original showrunner Frank Darabont and his successor, Glen Mazzara.

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15. Gimple says Rick's pal Morgan (Lennie James), who starred in one of Season 3's (and the series') best episodes, "Clear," will return in Season 4. "Gimple, by the way, wrote "Clear."

16. At one point in the new trailer, Hershel says, "We just lost 12 of our own." Does he mean 12 including the new characters and Woodbury transplants? And does this loss of a dozen people happen in one episode?

17. Time lapse between the Season 3 finale and the events of the Season 4 premiere: six or seven months, according to Gimple.

18. Tyreese may have a new BFF and a new girlfriend; Bob Stookey apparently takes a liking to him, as does Woodburyan Karen (Melissa Ponzio).

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19. More romance: Gimple told IGN.com that new character Zack (Kyle Gallner) will have a little somethin'-somethin' going with one of the "WD" characters, though it sounds like it may be an ill-fated affair. "He's not one of our major new characters, but you get to know a lot about him real quick," Gimple told IGN.

20. The prison will continue to be a setting for Season 4, but it may not be the only setting. In the Season 4 trailer, we see the survivors at various new locations, including what appears to be a supermarket or retail outlet of some kind, as well as a mobile hospital. And as Kirkman told the Hollywood Reporter, "The circumstances that could occur that would lead them from [the] prison remain a mystery, but they could be in the prison for the next two or three seasons or leave the prison in the very first episode of this season. It's all up in the air, and that's the way we prefer it."

21. Michonne (Danai Gurira) will ride a horse this season, with her trusty katana also at her side. How can that not be cool?

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22. For anyone who thought the survivors had gotten a little too proficient, and comfortable, in battling the walkers, be prepared for heightened danger ahead. In a Sirius XM radio interview in May, Norman "Daryl Dixon" Reedus said, "They've introduced a way to make zombies scary again, and they're terrifying. The new threat is just unreal. I can't of course tell you what that is, but it's brilliant writing."

23. Reedus, an accomplished photographer whose new photo book "The Sun's Coming Up … Like a Big Bald Head," was just released, says Season 4 is "so intense … These are our best scripts yet."

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24. The union of the Woodbury survivors with the prison survivors is civilized in at least one way: The children attend school, taught by Carol (Melissa McBride). Of course, readin', writin', and 'rithmetic are replaced on her syllabus by Walker Wastin' 101, with very sharp knives subbing for three-ring binders and No. 2 pencils.

25. In addition to fellow survivors, juiced-up zombies, and the wrath of the Governor, everyone involved with the series, from Kirkman and Gimple to Lincoln and executive producer Greg Nicotero, also teases a new, very powerful threat to Rick Grimes and his friends in Season 4.

Says Gimple: "It's a force that you can't just stab in the face, you can't talk reason to."

Says Kirkman: "Possibly the most deadly threat that they've faced thus far ... this new unseen force [is] going to be extremely dangerous and possibly more dangerous than anything."

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Says Lincoln: "There are ways that I find more horrifying when I read certain scripts this season that have nothing to do with conflict or zombies ... they've been very smart in adding that texture, that flavor, the horror back in the show."

And says Nicotero, who also directed the Season 4 premiere: "[The survivors walked] into a prison yard filled with 60 walkers, and it's like, 'We gotta kill them, move to another area and kill them, and take over the prison,' whereas it was important to me to make sure we kept that threat viable. The writers came up with several great devices, even storytelling-wise, that take it to the next level. You'll find out by the end of the first episode."

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26. The still-untitled Season 4 finale will be directed by Emmy-nominated "Breaking Bad" and "Game of Thrones" director Michelle MacLaren, reports ComicBook.com. MacLaren also directed the second episode ever of "Walking Dead" — "Guts" — as well as the season two gem "Pretty Much Dead Already," in which Rick and company kill the walkers in Hershel's barn, only to learn missing Sophia was among them.

27. Perhaps the best tease on what to expect in Season 4 came courtesy of Gimple at Comic-Con, when he told the fans, "It's going to get insane very quickly."

"The Walking Dead" Season 4 premieres Sunday, Oct. 13 at 9 p.m. on AMC.