The lead stars of "Sherlock" shared their thoughts about the upcoming Christmas special that brought them back in time.

After presenting an adaptation of Sir Arthur Conan Doyle's legendary character in the modern era, "Sherlock" series creators Steven Moffat and Mark Gatiss took the challenge of going back in time for the special Christmas episode of "Sherlock" this year. But actors Benedict Cumberbatch and Martin Freeman both admitted that they hesitated at first when they heard the plan.

"I genuinely didn't understand how they were going to get away with it," Cumberbatch told The Telegraph.

Cumberbatch also revealed how he feels about bringing his character back to his original era. "In the sense that he's a man slightly out of his time," the actor explained, "to put him back in the era that he's written in is a joy. Things I tried to impose a little on the modern version – his physicality, his stature – are done by the costumes: the collars, the deerstalkers and cape. It's a delight."

But perhaps Cumberbatch was more delighted to know that he could finally have a haircut for the episode. "We could get rid of that ridiculous bouncy lot of curls on my head," the actor said.

The Christmas special this year, which is titled "Sherlock: The Abominable Bride," will center on the quest of Sherlock Holmes (Cumberbatch) and his trusted friend Dr. Watson (Freeman) to solve the case involving the ghost of a woman who is said to have killed herself.

Freeman, meanwhile, said that Watson is more patient with Sherlock during the Victorian era. According to the actor, the Victorian version of his character lets Sherlock be the cocky detective that he is compared to the modern-day version of Watson. However, Freeman admitted that both versions of Watson believe that Sherlock is a genius detective no matter how brash he can be.

"Sherlock: The Abominable Bride" special episode will air on Friday, Jan. 1, on BBC1.