Wow, what an episode! Are we sure there is a Season 4 of Arrow? If not, this could have worked as the Series Finale, and it would have been one that I would have been completely okay with.
Last Time: Oliver left his friends to die at the hands of the Alpha/Omega virus as he marries the daughter of Ra's al Ghul and heads off to destroy Starling City.
Guess what! The rest of Team Arrow isn't dead (Go figure - it's not like any of us thought they were)! In fact, we come to find out that they have reversed engineered Oliver's immunity and slapped it on everyone before they were exposed (How come no one was like "hey, what's this weird film you're putting on my skin"). Awesome, now we just need to get the team out of this dungeon, which is where Plot Device...I mean Barry Allen comes in. After the previews and references in the latest Flash episode, I was really hoping that the Flash would be more help during the finale, but Barry ends up being on screen just about as long as Oliver was on the most recent Flash episode.
Quick! Everyone hop in this teleporter to Starling City - otherwise known as the plane that they've been using to get to and from Nanda Parbat. Meanwhile, Oliver reveals himself and attempts to take down the airplane, Ra's, and the Alpha/Omega at the same time. Obviously, this does not end well, which leads us to the discussion that Oliver hoped that he would never had (but we all saw coming) - Oliver facing the rest of Team Arrow and having to win back their trust. Luckily there is still a madman on the loose with a deadly chemical weapon! (How convienent for Oliver, otherwise that could have stayed awkward for awhile) The team spreads out to find the various League members who will be dispersing the bioweapon, only for one of them to come to Oliver and tell him what Oliver already knew: he still has one more showdown with Ra's.
(TIME OUT: Something just hit me. Where did these extra league guys come from? It was said there was only one parachute on the plane, so all the guys that jumped out couldn't have survived. Sure, you could say that Ra's had people staged in Starling, but that means that Ra's planted them there to die along with everyone else. Is that in the League contract? Warning - might be sacrified if everything goes according to the plan.)
In another great fight scene, Ra's and Oliver have it out, and of course Oliver manages to get over on Ra's, stabbing him in the chest. Only to be shot by the cops immediately afterwards and sent tumbling over into a dam. This is where I thought the season would end, with another bit of "Is he/isn't he dead?", so I was very relieved when the ATOM suit flies in and catches Oliver - only its Felicity, not Ray piloting the suit! Meanwhile, Thea shows up in the Arsenal get up and helps Diggle take out the remaining bioweapon dispensers.
The day is saved! Oliver realizes he doesn't need to be the hero, and decides to head off with Felicity. The team accepts Thea (finally) as someone who can hold up her own and she gets the "Speedy" name that the show has been teasing us with since the beginning. Diggle still doesn't trust Oliver, but will stay on to help protect the city (and become another masked hero? Who is he going to become?). And Ray blows up the top floor of his lab while working on tests to miniaturize parts of the suit (Oh no! Is he dead? Good thing I don't know he's a part of the new Legends of Tomorrow show or else that might be a big spoiler to that question!)
Final Thoughts: All in all, I thought this was another solid episode of Arrow, and another great season finale. As I said up above, this could have easily been the series finale for me, as I have no idea where they are going to go with Season 4. Having said that, I'm really scared now for the Flash season finale next week, as I'm wondering if Barry is going to go on a time travel trip that will dork up the whole Arrow-verse and wipe out a lot of what has transpired this season. If so, that'd be a big loss to us all. Don't let me down Flash!