The Sherlock one episode special (The Abominable Bride) aired on New Years day in the U.S. and the UK. While the episode was said to be a stand-alone episode that had nothing to do with the series, fans learned midway that the creators cleverly tied in the modern-day story arch and set the scene for season 4.
The third season ended with Moriarty (Andrew Scott) taunting Sherlock (Benedict Cumberbatch) on digital platforms as he is being sent away. This results in Sherlock being called back to figure out how Moriarty survived — assuming he did.
The one episode special started with a quick recap of all 3 seasons and then ventures into the episode, which is set in the Victoria era. Later in the episode, viewers are abruptly brought back to “reality”: turns out Sherlock is on drugs and he has taken himself to a case he previously heard of in order to figure out how Moriarty could have survived a gunshot wound to the head.
By the end of the episode, viewers learn that Moriarty is dead. Sherlock says it himself but seems to be onto the truth about how Moriarty’s presence is still around. "Of course Moriarty is dead," said Sherlock. "And I know exactly what he's going to do next."
In The Abominable Bride, a bride shoots herself and is then seen after her death killing her husband and other men. Turns out the bride staged her death with the help of like-minded allies, only to kill herself later in order to become a symbol for oppressed women. Should that story arch be the template for Moriarty’s return, then it would suggest that he has a team of protégés to carry out his notorious legacy.
Sherlock will begin filming season 4 this year.
