How Elementary Wraps Things Up For Holmes, Watson, and the Rest of the Crew

After faking his death to help bring down big bad Odin Reichenbach, Sherlock disappears for three years and embarks on an unofficial NSA career, even staying out of contact with Joan (although she knows he's still alive). After about a year away, he relapses and uses drugs, but never tells Joan about this, especially after learning that the adoption of her son has gone through.

He's summoned back to Joan's side when a message from Moriarty appears. The threat turns out to be a false alarm, but when Sherlock is about to leave again, he learns that Joan has cancer, so he stays in New York to be her family rather than taking the NSA up on their offer. A year later, she's cancer-free and the duo head to Bell's office to offer their services as NYPD consultants once again.

In the three years since Sherlock's disappearance and the defeat of Reichenbach, Joan has adopted an adorable son, Arthur, is still working with the NYPD, and has just written a best-selling memoir about her work with Sherlock. She signals him back when an associate of Moriarty's leaves a package behind for her, but hides the fact that she's been diagnosed with cancer. Sherlock finds out anyway and decides to stay with her and Arthur. A year later, her chemo has been successful, and the pair return to consult with the NYPD.

During the three-year time jump leading into the finale, Detective Bell gets promoted to the rank of captain, taking over the precinct from Captain Gregson rather than accepting offers from the US Marshals. He's also gotten married and become a father in the past few years. While he's none too thrilled about working with Sherlock after the Reinchenbach disappearance, he's still as staunch an ally as ever for Sherlock and Joan, and it's implied in the final moments that he's about to re-hire the duo as consultants.

Sherlock's former love and nemesis looms large in the finale, as her name is invoked in the case that brings Sherlock out of hiding: one of her associates appears to tell Joan that Moriarty is dead and has bequeathed something to Sherlock and thus to Joan, as his heir. As they investigate, it turns out that Moriarty is definitely not dead and that the "associate" was fake — and Moriarty is none too pleased that her name is being used under false pretences.

In the epilogue a year later, Sherlock and Joan attend Moriarty's funeral, but neither of them actually believe she's dead. Showrunner Rob Doherty confirmed that to TVLine. "I think it's pretty clear that she's someone that Sherlock and Joan will continue to come up against. We won't be able to see those episodes, but I liked the idea of her being out there and continuing to be a foe to Sherlock and Joan... Yes, I will say she's absolutely still alive."