For instance, what happened to Gerald Lydon? Are we to assume that he got placed in a facility? I thought we might see him before the end of the episode but we never did. Also, I'm surprised that when the police arrested Benny, they didn't bother looking for a wound that could've caused the blood spatter on the painting. Sherlock didn't even mention to mention it. The fiance murdering Natasha was mostly skimmed over and really the death was clearly just meant for them to find out about what she was investigating, but I did find the whole 'sociopathic gene' concept interesting. Even if it as at large irrelevant to the plot as a hole, I wonder if he would've succumbed to it had he not known he had it or if that side of his personality would've shown up eventually anyway. Oh, these things that I contemplate.
Anyway, I just felt like it all ended very abruptly. I also wish we could see more Gregson. That would be cool.
What I did like was Sherlock honing Joan's investigative skills and I even liked that she was awkward about it in the beginning. It made sense, as she was now an official partner, and she wasn't used to being pushed to the forefront. The whole situation with the laundromat was hilarious and Joan showing up with Bell at the end was great. I just like Detective Bell, okay? I also like that Sherlock's very encouraging of her, and I think that's sweet.
Overall, not one of my favorite episodes of the season but it was fine and still had its moments.
I'm probably missing things but oh well. Feel free to share your own thoughts! I always love to hear them. :D