"Sherlock" fans can expect big changes when the BBC crime drama series returns for its fourth season in 2016.

Series' creators Steven Moffat and Mark Gatiss, along with producer Sue Vertue, said that they are planning to increase the scale of the Primetime Emmy-winning show.

"The show has to keep evolving, it has to move on at a pace, I think," Vertue, Moffat's wife, told Radio Times during an interview about the special features on the show's upcoming Season 3 DVD.

"What we want to do for a fourth season is match [series three], but it's not a question of saying, 'Well we need a baddie on that scale [of Charles Augustus Magnussen],'" said Gatiss, referring to the previous season's primary antagonist played by Lars Mikkelsen.

"It's about trying to find stories that have that kind of scale to them," explained Gatiss, who also plays Mycroft Holmes on the series.

The Season 3 of the show, which explored how Sherlock's (Benedict Cumberbatch) faked suicide and John Watson's (Martin Freeman) marriage affected the dynamic between the duo,  was more character driven, according to Digital Spy. In fact, the previous season did not follow the standalone crime-solving theme that the first two installments had.

While some fans were not thrilled with the series shifting its focus from crime-solving to character comedy-drama, Gatiss and Moffat strongly believe that the dynamic between the two main characters is the strength of the show.

"An episode needs to be about something in their lives," Moffat said. "It is not enough for it to be a mystery."

"It is a series about a detective, it is not a detective series," insisted Gatiss. "The mystery of the week is as nothing compared to the relationship between those two characters and their increasingly large family of characters. That's the real heart of it, and that's why it's a success."

Gatiss and Moffat also revealed their intention to continue doing the show as long as possible.

"The idea, if we could, of finding Martin and Benedict in those chairs aged 50, sort of like the age that Holmes and Watson are usually portrayed... is sensational," said Gatiss. "It would be lovely to feel like we could do that."

Earlier this year, Cumberbatch also said that he would love to play Sherlock Holmes into his old age.

"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.