Tonight, Arrow will take its already impressive level of action to stunning new levels in a season finale entitled, “Unthinkable.” The name is a reference to events within the episode, but really, it could just as easily apply to the episode itself. Tonight’s season finale feature’s the long awaited showdown between Oliver Queen’s Arrow and Slade Wilson’s Deathstroke, plus the fallout from the return of Sara Lance and Malcolm Merlyn both of which took place last episode. All this, plus Roy Harper’s reawakening, some Suicide Squad-like action with Amanda Waller, Diggle and Harbinger, and the return of Katrina Law as Nyssa al Ghul. (And that’s just what we can tell you about!)

Before this show and particularly this spectacular season, the thought that we’d be seeing all of this on live action, primetime TV was…well, unthinkable!

To commemorate the end of his second year as Oliver Queen, and to see what we can learn about tonight’s can’t-miss event, we spoke with Stephen Amell about the episode, as well as where he sees the show going in the future, how he feels about entering a third year as a super hero, and if he has any advice for the man playing the newest DC hero to join the CW roster, Grant Gustin.

I read somewhere that you said the Arrow finale is the best hour of television this season. Or something to that extent.

Yeah, I said the Arrow finale is the best hour of television in 2014.

Those are some bold words! What can we expect from the finale?

The biggest fight in the history of TV in terms of just numbers and sheer size. There’s a bunch of different set pieces that I don’t think have been done on TV before. As far as our show goes, we’ve always been very principled in what’s a flashback and what’s the present, and we blur that line in the finale.

The show’s changed a lot this year, and it looks like next season is going to be quite a bit different than the seasons before. Do you find that sort of progression exhilarating? It seems like it’s rare for TV.

Yeah, one of the things that we had to focus on this year was the introduction of the Barry Allen character, and that enabled us to introduce powers. So we’ve had this mirakuru and these super soldiers, we’ve had people being struck by lightning, all in an effort to both sell the Slade Wilson character—who’s an awesome character—and introduce Barry Allen.

But now that The Flash has been picked up, which is wonderful, I think there will be elements in Season 3 where we get back to our roots a little bit and we take some of the creative license that we’ve earned over 46 episodes and explore some new stuff. But I would always want every season to be thematically different, otherwise I think we’d just lose track of time.

At this point, it seems like the Queen family’s been pretty decimated. Both of Oliver’s parents are dead and now things between Thea and Oliver are pretty estranged. In your opinion, how much does Oliver’s family mean to him, and what do you think all of this means going forward?

Oliver’s family obviously means a great deal, and there’s a moment toward the end of the finale where we see how much it means to him. But he also has new family now, with Roy, Diggle and Felicity. It will be interesting to see because it’s been three episodes after the finale since Moira’s death, but since we discovered Oliver in the aftermath, it’s actually only been one night in terms of real time. So we haven’t had a chance to see him reconcile his mother’s passing, and he is completely oblivious to the fact that Malcolm Merlyn is alive and that he has gone after Thea. It gives us a bunch of nice threads for next year.

Getting back to the finale, it seems like we can expect large-scale action, but last year’s finale was also really emotional. Should we be prepared to reach for the tissues this year?

For all of the action and gigantic set pieces, there’s one moment right in the middle of the finale which is actually a moment of silence and reaction where I think people are going to yell at their TVs. That’s going to be cool.

But it would be difficult to try to replicate what happened with Tommy last year, especially after what happened with Moira in episode 20. There are seriously impactful, emotional moments. One of the things I like about the finale is that last year, the sixth act in particular was just filled with action, racing and running, and then the Tommy scene. This year, the sixth act is very quiet. There’s no action. It’s characters speaking and reconciling. It’s a very different way to end a season, but at the same time, it will rile people up for season 3. Big time.

After playing the role of Oliver Queen for two complete seasons now, does he still excite and surprise you and in what ways?

Definitely. One of the things that I really loved about this year, though retrospectively it was sort of emotionally taxing, was how past the 13th episode or so, Oliver was really in a bad spot. We got to see him stripped down to basically nothing, and that was a really interesting and exciting thing to play for me because I’ve always liked the idea of our hero in danger. I like that other people can get the drop on him.

So it does excite me. I get to explore three more years of Oliver’s journey in the flashbacks, and what happens at the end of this episode in the finale changes Oliver. It will be interesting to see how the audience reacts to that.

Finally, you mentioned The Flash earlier, and it seems like the DC family is about to get a lot bigger on The CW. Any advice for Grant Gustin and the rest of Flash team?

No, I’ve met that cast and they’re all seasoned television veterans. I’m available to Grant if he needs any advice, but I trust him to follow his instincts and make the right choices. I would just say pace yourself, get your sleep and constantly remember that a pilot is one episode and a season is 22.

So in other words, you’re telling the Flash that it’s a marathon and not a sprint?

It’s more like two and a half marathons.

The Arrow season finale, "Unthinkable," airs tonight on The CW at 8 p.m. (7 p.m. CST). Be sure to watch till the end for your first look at The Flash, coming this fall to The CW!