For the first time, BBC's hugely popular series "Sherlock" will air four episodes in its upcoming third season, including a mini-episode called "Many Happy Returns."

In September, rumour about a Christmas Special episode of "Sherlock" spread like wild-fire on social networking sites. At the same time, Sue Vertue, producer of "Sherlock," however, was quick to squash that rumour on Twitter.

Sue Vertue had tweeted on September 19, 2013: "Sorry to squash the rumour but we haven't shot a #Sherlock Xmas special I'm afraid."

As confirmed by BBC One, the rumour has turned out to be true. There is a bonus Christmas Special mini-episode for millions upon millions of "Sherlock" fans. They can watch it on BBC's Red Button Service and online on Christmas Day, December 25, 2013.

According to the official synopsis of Christmas Day "Sherlock" mini episode, "Sherlock has been gone for 2 years. But someone isn't quite convinced that he's dead..."

The show will pick-up two years after Sherlock jumped down from the roof of St. Bartholomew hospital. We wonder who is not convinced about Sherlock's death. Is it Molly Hooper? Sherlock had said to Molly in the final episode of Season 2, "The Reichenbach Fall": "You're wrong, you know. You do count. You've always counted and I've always trusted you." Molly works in the morgue at St. Bartholomew's Hospital which counts as the right place to be suspicious about Sherlock being alive.

"Many Happy Returns" is a prequel to the three episodes of the upcoming season. "Sherlock" is scheduled to return on January 01, 2014. An empty hearse, travelling around central London, was used on Friday to announce the premiere date of "Sherlock" season 3. "The Empty Hearse" is the first episode of the season.

The Official Synopsis of BBC's "Sherlock" Season 3 Episode 1 "The Empty Hearse" is as follows: "... Dr John Watson has got on with his life. New horizons, romance and a comforting domestic future beckon. But, with London under threat of a huge terrorist attack, Sherlock Holmes is about to rise from the grave with all the theatricality that comes so naturally to him."

"It's what his best friend wanted more than anything, but for John Watson it might well be a case of 'be careful what you wish for'! If Sherlock thinks everything will be just as he left it though, he's in for a very big surprise..."