Odin Reichenbach is in the house, and the whole "previously" segment for this week is much of his scene from last week, a scene which continues for the start of this week's episode.
Here come the spoilers!
Odin Reichenbach is using his user data from Odker to predict future crime. And then making sure someone, not of any official capacity, stops those crimes in any way necessary. He's been doing it for a while, and he wants Sherlock and Joan on his team. He says he's been using a hammer, and he wants to use a scalpel. How Sherlock and Joan would actually work as a scalpel on potential criminals is a little unclear, but they just don't like him.
This makes Reichbach a sort of "reverse Moriarty," if you think about it. Moriarty planned crimes to help them occur so Scotland Yard never knows they exist. Reichenbach reverse-enginners potential criminal plans to stop them before anyone knows they exist. And Sherlock and Joan don't like it.
But, of course, as this is Elementary, Marcus Bell has a case for Holmes and Watson to solve before they can get back to dealing things they don't like.
Joan goes down the Marcus Bell path, and we learn that she can find the porn on your computer faster than anyone.
Sherlock sticks with the Reichenbach business and visits his NSA contact.
Joan and Marcus, however, interview a kink-porn producer. Good old Elementary!
Joan walks in on Sherlock wearing a goofy audio isolation helmet -- her walk-ins on Sherlock doing something off-kilter are the counterpart to Sherlock waking Joan up in weird ways. The show definitely has its comfy tropes.
Case with exotic details, more exotic details, more exotic details . . . Odin Reichenbach!!!
Sherlock has found the flaw in Odin Reichenbach's crime-predicting data-mining scheme, and find that Reichenbach is having innocents killed along with potential criminals: A bug in the master plan. But Sherlock says he and Joan want to join Reichenbach's scheme, if they get to make sure any potential criminal is actually going to do the horrible deed Reichenbach thinks that criminal is going to do. This is like the prequel to Minority Report, if you think about it.
HIPAA laws . . . oh, I do dislike when they bring HIPAA laws into my entertainments. They're not exotic or fun at all. And speaking of no fun, hey, where's Captain Dwyer this episode? Is Gregson still in the hospital? Is Clyde still in London? Odin Reichenbach needs to use his Odker data to predict when characters will come back to Elementary!
It's 9:51, this pregnant woman coming to the interrogation room must be the killer! She dated the heir to the wrestler-and-movie-star Bautista or something. Anyway, Joan Watson and Marcus Bell solve the case, which means Sherlock must be going to talk to Odin to cliff-hang the show.
Oh, no, it's Sherlock revealing the NSA guy is in Odin's pocket. He has a file of all Sherlock's friends and goes "Oh, wait, there's someone missing . . ." and for a moment, I think he's actually going to say "Jamie Moriarty." But it's just Joan, and the dude is threatening Sherlock's friends.
And, ah, here's Odin Reichenbach, with the quote of the closing scenes: "I can handle Sherlock Holmes." As much as I hate to use this phrase: Yeah, no.
They have to bring Moriarty back somehow before this is done. Let her get plastic surgery and be a new actress. But ol' Odin may be named Reichenbach, and he's just not the Reichenbach star we want.
Next week at the half hour mark, the final season of Elementary will be half done. On we go.