Could the BBC's popular adaptation of "Sherlock" change time periods? It is entirely possible as creator announces that at least one special episode will be set in Victorian times rather than the present. It's an unexpected move for the show and remains to be seen how they will manage the shift.

Creator and writer Steven Moffat revealed to Entertainment Weekly ahead of a South by Southwest conference on Monday that a special episode of "Sherlock," perhaps the show's Christmas Special, will be set in Victorian London rather than the 21st century.

"The special is its own thing," Moffat said. "We wouldn't have done the story we're doing, and the way we're doing it, if we didn't have this special. It's not part of the run of three episodes.

"So we had this to do it -- as we could hardly conceal -- it's Victorian. [Co-creator Mark Gatiss] and me, we wanted to do this, but it had to be a special, it had to be separate entity on its own. It's kind of in its own little bubble."

If it's in a separate bubble, one wonders how this special will play out. As a supposedly standalone episode, it will not follow the timeline and series of events started on season one. However, familiar faces will appear in the special.

Photos taken late in January during the filming of the special at the historic Gloucester Cathedral show actor Amanda Abbington with the cast, reported the Daily Mirror. She plays Dr. John Watson's wife Mary, only to be revealed as a former assassin in "The Last Vow." What role she will play in the Victorian set special remains unknown.

"I don't know the plot but they moved a single bed into the crypt before they started filming," a church insider revealed to the Daily Mirror.

"They also brought in some other props to put round the bed. I think they are pretending the crypt is another location and aren't using Gloucester Cathedral as part of the story."

According to Entertainment Weekly, filming of the special Victorian episode has ended, and though no date has been given, it is expected to air in the U.K. sometime in December.