'Sherlock' season 4 air date, spoilers: New season to premiere by January; Grim fate awaits major character?

A lot of rumors are going around about "Sherlock" season 4 and the latest one involve the purported death of Mary Watson (Amanda Abbington).

The previous season was a very big step for the character having revealed her past as an assassin. Mary appears to be done with that life, but the skills she acquired are still very much there.

The revelation was made in order for her to be more involved in Sherlock (Benedict Cumberbatch) and her husband Watson (Martin Freeman) in their undertakings in "Sherlock" season 4, proving that she too can handle some action.

"We deliberately set out to make it like the best times for the three of them as a new team, that they would really have a great time," executive producer Mark Gatiss said earlier this year via Den of Geek.

With that said, Mary is yet to completely turn her back on her old life and that the new season will mark her return to the dangerous life she once had.

This will reportedly lead her to her demise in "Sherlock" season 4, according to the latest reports. While she has the "super agent" chops, their next mission will allegedly end her life.

There's no information to corroborate that yet, though. In fact, Gatiss and fellow EP Steven Moffat have big plans for Mary both as an asset for Sherlock and Watson and as a parent.

In "Sherlock" season 4, Mary and Watson will experience parenthood – both the fun and the challenges that come with it. This suggests that there are big developments coming to Abbington's character this season.

But if the report about Mary's untimely death comes to fruition, these developments will certainly make her death more heartbreaking. The season is said to be very dark so death may be involved.

On the other hand, Gatiss teased to BBC Breakfast that "Sherlock" season 4 will be "the best one yet" as quoted by Mirror. "We're very excited about it. I think it's the best one we've done, it's very big chewy stuff, meaty," he continued.

"Sherlock" season 4 will premiere on BBC early next year.