To borrow a quote from Gandalf: "the board is set, the pieces are moving..." which is an appropriate summation for this episode, and the last episode, and quite possibly the next episode as well (I haven't seen it yet).
Though I can get a bit snarky in these reviews, I do enjoy Arrow (I wouldn't be writing about it if I didn't) and I'm in it for the long haul. That said, there's been some tripping up on the way to this season's finish line, and this episode in particular felt very "bitsy" in terms of what it was trying to do.
Which was to move things into position for the finale, deal with the fallout of the last episode's revelations, introduce two new characters for the spin-off, present the possibility of a mirakuru cure in the flashbacks, and bring back Roy. There's no thematic or narrative unity in any of those tasks, and as a result this episode felt like a checklist of things that had to be ticked off in order to proceed to the next one.
So, let's go through them all one by one.