Professor Jim Moriarty returned on BBC One's "Sherlock" in the Season 4 finale aired on Jan. 15, Sunday. He is played by Andrew Scott, an Irish television, film and stage actor.
Scott joined the cast of crime series "Sherlock" in 2010, and played as the criminal mastermind who Benedict Cumberbatch's Sherlock Holmes described as the "Napoleon of crime." The character engaged in conflict with Holmes before supposedly killing himself in "The Reichenbach Fall."
The scene in "Sherlock" Season 4's finale showed Moriarty in a flashback sequence. In the episode, he collaborated with Sian Brooke's Eurus, Sherlock's secret sister before he died.
The 40-year-old Moriarty actor had been often asked by fans if he would return to the show, Scott told The Telegraph during a screening of an episode of the TV series. He revealed he spent the last six months of his life "under wraps."
"Sherlock" Season 4 episode 3 likewise unveiled that Sherlock's dog Redbeard was killed by Eurus. The plot about Redbeard was originally a joke that became a storyline, co-creator and actor Mark Gatiss shared with the online news site during the screening event. It was a bit of a reference to the fact that Sherlock's pet dog lived on a farm.
As for the future of the show, writer Steven Moffat revealed they were not planning Season 4 Episode 3 to be the final. However, it can possibly be.
"We could end it there," Moffat told the digital broadsheet. "We couldn't have ended it on any of the previous series because they always ended in walloping great cliffhangers."
Moffat added that leaving the scene at Rathbone Place is actually to make their comeback, in case there will be any, easy. They can have Holmes knock on the door and ask Dr. John Watson if he wants to play outside.
Meanwhile, Moffat and producer Sue Vertue failed to show up to an invitation by Channel One in Russia for a Moscow master class, according to The Hollywood Reporter. Channel One which airs the BBC One series, is currently the center of a leak controversy and is under investigation.
Here's a preview of "Sherlock" Season 4 episode 3: