Omma is the informal word for mother in Korean (엄마). I remember something Korea was mentioned earlier in the episode. Maybe important?

Many of the characters mirror each other...

I too noticed the continuous theme of mirrors and reflection and am curious as to the meaning. Sherlock filming has always used reflection for some creative shots, but this was overly prevalent with some sort of mirror or reflection in every single scene.

I almost feel like they could be trying to reach deeper into the characters true self, a self realization. I think the playful repeat of the line, "You see but you don't understand," plays a bigger role in the plot than just a gag scene.

Sherlock finally realizes that there are consequences to his arrogance that ultimately led to the death of a dear friend. He's always been able to sweep in, save his friends and outwit the bad guys in the past, but lately he's been off his game since he doesn't understand human emotions and why people do what they do. We see him looking for help in a therapy session with a giant window in the background, full of light shining in.

John sees in his reflection his true self, not the perfect man and loyal friend others see. That's why I think we see Exx relected in the airplane window on the way back to London.

I think Mary knew more than John thought, maybe even about Exx. So then the question is who is Sherlock suppose to save John from? Himself? Exx? In my opinion she knew that Sherlock is the ONLY person that can save John, hence why she jumped in front of the bullet. She was always willing to sacrifice herself for John. I think she knew that her previous lies and deceptions broke the trust in their relationship so she could never save John, especially if the threat is from himself. One thing is for sure... It's going to be hard for Sherlock to save John without his trust, which was destroyed in the broken vow. Maybe that is why he will have to go to Hell?

It looks like in the next episode that things must be at least somewhat repaired since we see John and Sherlock working together, but Sherlock really seems to be losing it.

Can't wait to have more revealed next week!! Sherlock never disappoints! :D

Love hearing everyone's insights!

Cool.