Those awaiting word from Baker Street may already breathe easy with some details now out on the return of television's favorite detective from 221B, Sherlock Holmes. Thanks to Arwel Wyn Jones, fans will actually have concrete and substantial proof that "Sherlock" season 4 is well on its way to fruition. Jones is a BBC production designer on the show, and he has posted some photographs on his Twitter account showing the ongoing work on the set of "Sherlock" as the team gets it ready for filming in the spring, sometime in April.

It would also be a relief for avid viewers of the show that the main cast from last season will all be joining a new addition to the family. So Benedict Cumberbatch and Martin Freeman will be reprising their central roles of Sherlock and Watson, respectively, as well as Amanda Abbington as Mary Watson, Jonathan Aris as Anderson, and Louise Brealey as Molly Hooper.

The new cast addition is someone who was hinted at in the last episode of season 3 where Mycroft murmurs something seemingly unrelated regarding "the other one" as he defends Sherlock while being accused of favoring his brother. Talk of a third Holmes brother has pegged Tom Hiddleston (Loki in "Thor") for the role. Cumberbatch himself has given hints about Sherlock's family background in an interview with the Latin Times.

Cumberbatch said, "You find out about Sherlock's background. You find out that he comes from a truly stab family."

Rumors of a devastating death in the series has also gone around and seems to be unerringly pointing at Mary. It is remembered that Mary had been pregnant in the previous season; she is said to die in childbirth.

Freeman shared on UK's Telegraph, "While we play fast and loose with the original stories, we generally follow the trajectory of what Conan Doyle did. So he [Watson] gets married, and then Mary dies - so at some point presumably she'll die."

As for Moriarty, showrunner Steve Moffat confirmed "Moriarty is dead. He shot himself in the face. What more do you want?"

"Sherlock" season 4 will premiere sometime in January 2017.