Sherlock: Did you miss me? Kyiv's metro trains display hacked image of Moriarty

The mysterious images of Sherlock's fated nemesis have been spreading across Twitter like wildfire.

The game is afoot in Kyiv, Ukraine.

Snapshots from inside the capital's metro trains are making the rounds on Twitter, showing the interior's hacked display screens featuring an image of Sherlock's nemesis, Moriarty (Andrew Scott). Alongside that phrase which sends shivers down every Sherlock fan's spine, "Did you miss me?"

Usually, the screens function to loop clips on the metro's usual safety regulations and general etiquette rules. The hack appears to directly reference the series 3 finale, in which Sherlock is called back from his highly dangerous mission in Eastern Europe by the supposedly deceased Moriarty popping up on every screen in central London, repeating the ominous phrase, "Did you miss me?"

A covert marketing move from the BBC? Apparently not, as a major Ukrainian news network reports that the images were indeed the work of hackers, with Kyiv Metro releasing a statement that the incident is currently under investigation. 

What's the end game for these hackers? Are they attempting to reveal flaws in the transport system's security? Or merely trying to spread the gospel of Benedict Cumberbatch? Who knows. 

Fans have been left in the dark about Moriarty's fate thanks to the end of the last series; though he'd supposedly killed himself in the series 2 finale "The Reichenbach Fall", the series 3 finale appeared to suggest some form of return from the character. The New Year Special, "The Abominable Bride", solved only a little of the mystery; with Sherlock uttering the mysterious phrase, "I never said he was alive. I said he was back." 

Series 4 of Sherlock will air in 2017.