George Clooney hits the set of 'Downton Abbey' Christmas special

George Clooney and Downton Abbey fans have been not-so-patiently waiting for their first glimpse of the handsome actor on set of the hit show, and here it is! The first photos released of the newlywed have him posing with actor Hugh Bonneville.

The photos don't give a clue to the episode's plot (which remains a mystery), but we do know that Hugh, who plays patriarch Lord Grantham, personally asked George to guest star on the annual Downton Abbey Christmas special after they collaborated on The Monuments Men.

George Clooney and Hugh Bonneville in Downton Abbey

The promotional shots see the pals pose for a serious photo and one that looks like the pair is up to a little mischief. In both photos, they are holding a clapboard for Downton with details for a charity fundraiser, Text Santa.

The 53-year-old actor filmed his scenes at Highclere Castle with Hugh and Emmy-nominated actress Michelle Dockery before his high-profile September wedding to Amal Alamuddin. While he was on location at the Hampshire estate, many suspected his presence there was because he and his now-wife Amal were considering the famous home as a possible wedding venue.

"All the plans have been shrouded in secrecy because George was determined for his role not to leak out," a source told The Sun newspaper.

The source added: "All the other cast members and crew were sworn to secrecy. It's amazing it's taken four months for someone to find out. This is the biggest moment in Downton history and shows it's now the biggest drama in the world."

George and Hugh pose for a serious photo

One secret did happen to escape the set: Tom Cullen, who plays Lord Gillingham, revealed that George had planted a kiss on Dame Maggie Smith, the show's matriarch.

"I know he gave Maggie a kiss and she collapsed onto the sofa," he told British talk show host Lorraine Kelly. "He’s a very handsome man, isn’t he?" he added.

Watch a sneak peek of George in the Christmas special with Elizabeth McGovern, who plays Lady Cora, and Lily James, who plays Lady Rose, below:

While British viewers have already been enjoying the fifth season of the series, which concludes with the Christmas special, American fans have to wait until it starts airing on PBS January 4.

More about