It has been more than a year since the third season of "Sherlock" has ended and fans are still waiting for the return of their favorite detective. Unfortunately, it seems that it will be another two years before that happens.

But fans need not despair as a Christmas special is already in the bag and will reportedly air either late this year or early 2016. The "Sherlock Christmas Special" is said to be set in 1895 Victorian England and will be based on the short story "The Adventure of the Blue Carbuncle."

Production for the fourth season of "Sherlock" is said to begin by 2016 but showrunner Steven Moffat and writer Mark Gatiss are already warning fans that the next season will be "darker" and "devastating."

According to Moffat, the next season is about consequences.

"Chickens come to roost," he explains. "It's dark in some ways…it's hilarious and exhilarating some days, but some days it's going to be bloody frightening."

One victim of these consequences is rumored to be John Watson's (Martin Freeman) wife, Mary. Freeman acknowledges this and points out that even though they use the original stories as a jump-off point for the series' plot, they "generally follow the trajectory of what Conan Doyle did."

"So [Watson] get married, and then Mary dies – so at some point presumably she'll die," said Freeman.

But ever since John Watson has gotten married, fans have also been wondering when, or if, romance is in the cards for Sherlock (Benedict Cumberbatch). Irene Adler's (Lara Pulver) return would certainly get fans going, as the two had an undeniable connection back in season two. Pulver and Cumberbatch appear to be supportive of the idea, but Gatiss (who also plays Sherlock's older brother Mycroft) is a tad cautious about bringing back the woman who might be Sherlock's equal. But even if Adler does not return, women will play a stronger role in the next season.

According to Moffat, a female perspective on Sherlock and his friendship with John Watson would be enlightening.

"So we've expanded hugely the part of Mrs.Hudson [played by Una Stubbs] because she didn't speak in the original," Moffat explained. "And we brought Molly in."