Official Description of Season 3:

Series Three sees MERLIN return with the familiar blend of magic, monsters and mayhem. But when secrets are exposed and old friends choose new sides, it is clear that the kingdom will never be the same again. Morgana is finally found after months of absence, and non in Camelot rejoice more than the King himself. But Merlin remains suspicious of his old friend, for, despite what she may have others believe, Morgana wants only one thing: to take over Camelot and she’s prepared to do whatever it takes to achieve it. Life changing decisions must be made as the boundaries of love, duty and friendship are pushed to their utmost limit, and the mettle of each character is tested in unimaginable ways. But in an uncertain future, only the strongest will survive.

Syfy Expected to Air Season 3 in Early 2011:

After a successful summer run on Syfy, Merlin will return for a third season, the networks tells TV Guide Magazine exclusively. The next 13 episodes of the series, based on the mythical legends of Camelot, are expected in early 2011, shortly after premiering in the U.K. on the BBC.

Merlin's first season aired in the U.S. on NBC last summer with mediocre ratings, by broadcast standards. The series moved to Syfy for Season 2 this summer, drawing a healthy 1.72 million viewers (an 81 percent increase for the network in the Fridays-at-10pm timeslot) and building a cult following, as evidenced by a well-received panel at last month's Comic-Con.

"We are thrilled that Syfy will be broadcasting the third series of Merlin,"series creator/executive producer Johnny Capps says. "The upcoming season will add an exciting new twist to Merlin's ongoing struggle to protect Prince Arthur, as well as thrilling audiences with bigger and bolder action sequences, stunning CGI monsters, mysterious villains and comic fun for all the family."

Note - Thanks to Rebecca Rodrigues for finding this at TV Guide's Official Website and sending us the article and link.

Season 3 Relationships:

We’re not sure how reliable this information is. And if it is, if it’s for the first two episodes or entire third season. We’ll classify these as rumors for the moment.

The shippers that will be most happy during Season 3 are apparently going to be Merlin/Arthur, Morgana/Morgause and Arthur/Morgana. Those who ship Merlin/Gwen and Gwen/Morgana will be most upset. But for different reasons. The later will be unkind while the earlier will just be there when they need to interact. Those who are fans of Arthur/Gwen relationship will be in for a rocky road with both some happy and tense times.

New Spoilers Added on 8/25/10:

Episode 1 Logline 1 - Merlin (Colin Morgan) must find out who placed a deadly spell over Uther (Anthony Head) in the third series premiere.

Episode 2 Logline 1 - As Cenred's (Tom Ellis) forces attack Camelot, Arthur (Bradley James) leads his men into battle and Merlin (Colin Morgan) has to stop the evil Morgana (Katie McGrath) from unleashing a skeleton army.

The first episode features a character that is described as Arthur's illusion of a sodden boy.

Morgause will accompany Cenred and his army on, at least, their journey to Camelot.

Sir Leon will be in the first episode. If he will be in the second episode, which is the conclusion of the premiere, is currently unknown.

Merlin gets to fight alongside Arthur, using a sword, in the second episode.

Costumes in the first episode include Morgana's lighter green dress, Sir Leon's casual armor from The Nightmare Begins and Arthur's traveling clothes from The Last Dragonlord. Although it's hard to tell based on the quality of the source, it looks like Gaius will be wearing his brown robe from the first season in some scenes.

Episode 3x1 and Episode 3x2:

A year has passed since Morgana (Katie McGrath) disappeared, and Uther's (Anthony Head) desperate attempts to find his ward have almost destroyed his army. Following an ambush in an eerie forest, a bruised and bloody Morgana emerges, claiming to have been held prisoner by bandits all this time. When Uther begins to have terrifying visions, Gaius (Richard Wilson) and Merlin (Colin Morgan) realise that Morgana is a traitor and has the king gripped by a dark enchantment. Merlin releases Uther but there is worse to come: Cenred (Tom Ellis) has joined forces with Morgause (Emilia Fox) and a huge army is swarming towards Camelot.

As Uther struggles to recover, Arthur (Bradley James) must take charge. In the midst of the battle, Morgana quietly slips down to the vaults and unleashes a gruesome army of skeletons; she wants vengeance for the deaths Uther has caused in his quest to destroy all magical beings. Merlin confronts her, and as they fight he almost reveals his own gift. While her back is turned he uses magic to collapse the ceiling, knocking Morgana unconscious. As her spell breaks, the skeleton army crumbles and Camelot fights on to victory. To Merlin's horror, Uther mistakenly hails Morgana as Camelot's savior - and the king is more determined than ever to keep the forces of magic from his gates.

Note - Amazon.co.uk has changed the description at the below link to remove the major spoiler bits.

Random Spoilers for Other Episodes:

The role of King Cenred will be portrayed by Tom Ellis. Cenred's costume is said to resemble a cross between Ares from Hercules/Xena and Sir Guy from BBC's 2006 "Robin Hood".

Scenes featuring Mark Williams as a Goblin and an older woman nagging Gaius were filmed during block one.

Block two episodes feature Georgia King as Elaine and John Hopkins as the treacherous Sir Oswald. Simon Williams guest stars as a noble, possibly a king and father to Georgia's character, in a two-parter. Miriam Margolyes also guest stars as Grunhilda in the same two-parter.

A scene was filmed at the village set featuring Morgana, an elderly Morgause, an apple and possibly Gwen.

An early episode features Merlin and Arthur in a bar fight.

Gwen will meet her brother who she may or may not be aware of. According to SFX Magazine, Gwen's brother will be in three episodes.

Pauline Collins will portray the love interest of Gaius in an episode.

Sir Leon is featured in episodes from at least blocks one and three.

Block three episodes feature the crystal cave, future Roundtable knight Gawain, Arthur viciously training with Merlin, a verbal spat between Merlin and Gaius and what looks like Merlin, Arthur, Gwen and Morgana going somewhere together.

Angel Coulby said at Comic Con France that the friendship between Morgana and Gwen is done.

Warwick Davis will guest star in an episode as a character named Grettir.

Speculation and Rumors:

An episode with a tournament that includes a sword fight between many knights on horseback at the jousting arena.

There are unconfirmed rumors of a scene in which Morgana slaps Gwen.