[Spoiler Alert: If you haven't watched this week's episode of Arrow, do not read forward. Big spoilers ahead! Seriously!]

Did you see that coming?

While most of Arrow Season 2 Episode 20 was based around the crazy exploits of Roy Harper, the ending sent a shock through the system of all loyal viewers:

Slade - taking his vengeance against Oliver to new heights - forced Oliver to choose between the lives of his mother and sister. Before he could do so, however, his mother made the ultimate sacrifice. RIP, Moira Queen.

Below, TV Fanatic has the exclusive first interview with Susanna Thompson, who has played Moira Queen since the very first episode of this CW smash.

And while her character's death was a tear-filled stunner, the actress reminded us that it also will propel the stories of Oliver and Thea forward in new and fascinating ways...

TV Fanatic: Though I’m not happy that Moira is gone, I have to say the way it was done was very fitting for the show and where the storylines have been heading all season.

Susanna Thompson: Yes. And also just the investment that you as an audience member have, it’s a similar vibration to the emotional journey particularly that Thea and Oliver have been on with their mother. And so I think that’s what’s interesting to me, too, is how it lands for them, it could be a very similar way as how it’s landing to the audience. It catapults Oliver’s story, then Thea’s story in many ways.

TVF: Talk to me about that conversation when you found out this was what was going to happen.

ST: Those conversations are mixed. In the back of your mind one never knows in a show like this who’s next. So there’s that. And then when you hear that it’s going to be your character, there’s a sense of shock. There’s a sense of sadness and there’s a sense of acceptance as well. I think particularly for Moira. If you looked at the current journey, the comic book journey for her, I think Oliver was five when she died in the African safari. I used to joke with people like David Ramsey that once we hear that Moira’s got a ticket to Africa, then we know what’s going to happen.

But even with the joking, you’re never ready for that moment. And I have to tell you, the biggest impact is saying goodbye to people. I mean, because I’ve been around the industry for a while and you say goodbye to shows. And this is the first time I’ve been involved in a show where my character actually died. So that was different.

TVF: What was the final scene that you shot? Was it that last scene with Slade, Oliver and Thea or maybe one of the flashbacks?

ST: The very very last scene was one of the first scenes of the episode. It was when Thea comes in and interrupts my interview. That was the last scene that I filmed.

TVF: I thought the flashback story with Oliver’s unexpected pregnancy was so fitting because it really showed Moira being a mother to Oliver.

ST: I think if I were a mother I would do things a lot differently than Moira does but you get a sense in those flashbacks of the secrets that perhaps she’s already keeping, just in terms of what she’s negotiated already to that point with Robert, that he doesn’t know and Oliver doesn’t know. And she’s, of course, had to put out fires with his teenage years.

But this is the biggest one by far at that point in flashbacks. And I really do believe, as I was talking to [Executive Producer] Marc Guggenheim, I really do believe that she was trying to hold onto a hopeful future for him. And I don’t know that they intended it, but I also think, yes, she’s putting out a fire that she hopes Oliver will not discover. But I also think she’s very sincere in many ways when she says ‘this is my first grandchild.’

TVF: I’m sure all those scenes were tough for you to shoot but was there a difference in that flashback because it really showed the emotional connection you were having with Oliver?

ST: I’m telling you, it was to me, I think, and I think that Stephen would say the same thing. It was a very gratified, satisfying way to end with Moira. To really go in to her love and her ease with Oliver. The two of them really get each other and you see that in a flashback. And for Stephen and I to be able to go there as actors in those scenes was really, to me, very satisfying and, at times emotional.

The last scene where he tells her that Sandra lost the baby. In the flashback, the ‘my beautiful boy’ line from the pilot. I mean, it’s a beautiful way that Marc wrote that in. And I already knew that when I read it. But it’s not until I was actually filming it did Stephen and I started to really feel the depth of that, because it takes you back to the pilot, the beginning of all this as actors, not only just the character stories but as actors, our developing of these characters, it takes you all the way back there.

But, as we were filming it, it hit me at one point. Like my cellular memories remembered in the pilot that I also gave him a kiss and I did that and it was almost like I had to really reel in the flood gates to get through the scene. And Stephen had his own emotional journey we couldn’t talk to each other in between takes on that final scene because we were going in these very, very different places, both very emotional.

TVF: And Moira tells Oliver in the present day that she’s known for a while that he’s the Arrow.

ST: I loved it.

TVF: And you always said, even from probably the first season when we’ve talked, that Moira probably knows more than she’s letting on.

ST: Exactly. And of course, logistically, when and where did she know? I often said in [Arrow Season 1 Episode 14], ‘she would recognize his chin! She would recognize him!’ But you know, you suspend that and you move on. You go, ‘okay, she doesn’t [know].’

But when does she find out? And I think they were smart about when they decided. And I then tracked it to just during that scene that Moira and Oliver have in [Arrow Season 1 Episode 21] when he says, ‘Somebody’s got to do something.’ And I was thrilled and so was Stephen that that was coming out because we had often talked about that. And I wasn’t sure if it would. I wasn’t sure if they would logistically be able to do it.

Oliver and Moira had been very parallel. They’re characters that know each other and they are characters actually that maneuver in the world very similarly. You could go back and forth between their stories and what they’re hiding and what they’re doing and who they’ve become.

TVF: In the car crash scene, Moira was about to say something about Malcolm and I’m curious if you knew what she was going to say or…?

ST: The script said Malcolm, dot dot dot. If you’re an actor and you read that and you’re watching this episode, you could pretty much guess, I think, what is she talking about? It’s time to turn a new page. And she’s talking about her lying. So you could only guess, and I can’t tell you, but you can guess. I think it’s clear. If I were just an audience member I would know exactly what she was about to say and it’s perfect that she doesn’t get it out.

TVF: And now let’s talk about the death scene. Were you on a stage or were you actually outside? It must’ve taken awhile to shoot.

ST: Yes, it was outside, it was in the park in Vancouver, in the cold, in the rain. I knew what the physical conditions were going to be. I didn’t know about the rain. But I also knew that I had everybody’s support. We shot that scene the second day of filming in the episode and I was actually glad when it was over because we could get down to business, because we weren’t anticipating it anymore.

Stephen is so kind and, in many ways, protective of us as actors, but to me playing his mother, he said, ‘I just want you to know that if there anything you need for that scene, please speak up. If you want to be filmed first, you just say what you need.’ And I said, ‘thank you, sweetheart.’ But I knew that whatever happened that night it was going to be fine. And I took my contacts out and just went into a zone. And Willa went with me. And Stephen was going to go there. And we did one rehearsal and then Willa came over and just started hugging me and I said ‘we can’t go there right now.’

It was emotionally draining for all of us and the director (Doug Aarniokoski) barely talked to me during the rehearsal and during the filming of it. He barely mentioned anything, because we all came with everything. And I knew it. It was electrically charged and the crew didn’t speak. Everyone just stood there and there was very little chit chatting and frivolity. None of that.

TVF: And in that final scene we see Moira both as a mother and also as a hero with her sacrifice. Do you see it that way?

ST: I clearly do, Jim. Absolutely. And the fact that she knows who Oliver is. And they originally had that line, ‘There’s only one way tonight can end.’ They originally had, in the script they had [Moira] standing up, turning, and saying that whole line to Slade but with the logistics of the scene and the getting up in heels and the slowness of it and she’s staring right at Oliver the whole time. I knew that line had to go to Oliver. And in doing that, it recalls the knowingness between Oliver and Moira. I mean, he knows what she’s saying that to him, it landed even deeper for him, that sacrifice. And truly that is, that is the mother being the hero there. And in many ways, not just for her children but for the bigger landscape of what she knows he is now.

TVF: My last question would only be what’s next for you? Have you recovered from all this?

ST: Well, I think I’ve recovered. I won’t really recover until the season has aired. And then you never know. I might be visiting them, who knows, if there are flashbacks or what not. I know that they were very happy with the flashbacks. But moving on from Arrow, auditions but currently I’m just very excited. My husband is going to be teaching in Slovenia and we’re piggy backing a trip to Paris. We’ve never been to Paris and I’m so excited. I think the trip will be a great transition for me, and when I get back I’ll be ready then to work again, I think.

Arrow Season 2 airs Wednesdays at 8/7 on The CW.

Jim Halterman is the West Coast Editor of TV Fanatic and the owner of JimHalterman.com. Follow him on Twitter.