This Is How Elementary Ends For All Its Major Characters

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.