The Finale is now upon us soon.
Sherlock Holmes fans most likely took note of the name of the character Odin Reichenbach. In the original Sherlock Holmes stories it was the Reichenbach Falls where Sherlock Holmes dies. I'm not sure if this is a spoiler, but I suspect we will see Moriarty's return and having something to do with Odin Reichenbach. Perhaps they fall of Odin Reichenbach's building, but a fall of some sort is possible.
NOT SPOILERS, Just speculation.