Epilogue time! Holmes is up on his roof, looking at his bees. Watson comes up with an update about Moriarty. She was recorded confessing to the Theophilus caper, so her Macedonian Denars have been frozen. Holmes sums up: "My nemesis has been defeated." Watson asks if he needs to find a new one. Holmes changes the subject to that rare bee in the box he got a while back. It's its own species, so it shouldn't be able to reproduce with his regular bees. But it has! So that means he has an entirely new species. A new bee crawls out, and it's the first one of its kind. Holmes names it Euglassia Watsonia. Watson asks, "You named a bee after me?" He did. Watson decides to stay on the roof and watch the bees be born with Holmes.
And that's it! I'm pleased that Natalie Dormer wasn't killed off, since it means there's a chance she'll be back at some point next season.