a theory (spoilers of course)...
I believe Ra's al Ghul was the mastermind all along with "The Undertaking" and Malcolm Meryln was part of the League of Assassins to return to fulfill in that mission in "destroying and rebuilding" the Gallows. The flashbacks all tie into what is going on in the present and the League of Assassins were overall behind everything that was going on in the flashbacks. I believe Moria KNEW where Oliver was the whole entire time, but kept her mouth shut in fear of Meryln, and it was DELIBERATE as to why Oliver remained on that island for that long period of time when he could of been rescued at any point of time. I suspect that this is why she told the lawyer in this episode that she could not reveal everything in fear of completely losing her relationship with both Oliver and Thea. As much as she has knowledge of everything else, from the bombing of the ship as well as resalvaging it, Meryln's overall plan, the fact that her new husband was kidnap and she was in on what really happened and why, I am totally got a strong feeling her secret was she knew where Oliver was during the time he was on the island and didn't have a rescue team to come out to save him.
I also believe that Sara survived too, and her mother was indeed right that she made it to another island nearby. I believe that this was the same island that the League of Assassins done their training at and this was when she transformed to Black Canary. I know there's so many holes to be filled up, but this episode really tied a lot of things together to for me at least, realized that ALL OF THIS is connected, and everything that went down in the past is all part of what is happening in the present.
#showisamazing
