Benedict Cumberbatch, who plays the titular role in Primetime Emmy-winning British crime drama series "Sherlock," has teased that the upcoming Christmas Special and the three-episode Season 4 of the show are going to be "phenomenal."

"I can't give any plot away... but their pitch for the Christmas special and the series beyond that is just phenomenal," the 38-year-old British actor told Empire magazine via BBC America. "We've never seen [Sherlock] being really pressed yet, so that will be interesting."

Martin Freeman, who plays the role of Dr. John Watson in the series, previously opened up about the upcoming season, too.

"It's going to be full of surprises for you, and for us and for everybody," the 42-year-old "The Hobbit: An Unexpected Journey" actor told BBC Radio Wales last month. "I think we just know to expect the unexpected now."

"The plans they have got for the overarching series - oh man, it's just so exciting!" he added.

Speaking at this year's Primetime Emmy Awards night last month, co-creator Steven Moffat said that they have a plan to "top" the last season of the show.  "I do think our plan is devastating," he said. "We've practically reduced our cast to tears telling them the plan ... we're probably more excited that we've ever been about 'Sherlock,'" according to Entertainment Weekly.

Fellow creator Mark Gatiss, who also plays Mycroft Holmes in the show, also teased about Season 4 at the HBO after-party.

"We're going to try to take it somewhere we've never been before - and I don't mean outer space," said the actor who will also reprise his role as Tycho Nestoris in "Game of Thrones" Season 5. "It will be challenging place to go. We always start with a re-introduction that builds toward a darker climax - we might just be going darker [from the outset]. We got a very, very good set of ideas."

Meanwhile, in the same interview with Empire magazine, Cumberbatch also said that he would like to close the series "on a high," but they will continue to do it until they do not want to do it anymore.

"As long as the ideas are still there and the audience still wants it and as long as Martin [Freeman] and I are not so infirm we can no longer remember the lines and shuffle round the set. I'd love to do it into old age, I really would," he told Empire magazine via The Mirror.

The three-episode Season 4 of "Sherlock" is set to be aired in early 2016, following a full-length Christmas 2015 special, which will go into production in January 2015.