When Arrow returns for its fourth season on Wednesday, the titular superhero will be enjoying his retirement, living in domestic bliss with Felicity (Emily Bett Rickards). But when Oliver (Stephen Amell) is forced to suit up once more and return to Starling City, he'll discover his newfound happiness challenged by his darkest enemy yet.

TVGuide.com spoke with executive producer Wendy Mericle to find out everything you need to know before watching Season 4.

How will Oliver's time away from Starling City have changed him?
Mericle:It's interesting. He's going to be in a really good place at the top of Season 4. As we saw in the finale last year, he kind of rode off into the sunset with Felicity and he is genuinely very, very happy. I can't tell you where he is, but he's in a city far away from Starling City. He and Felicity are living in domestic bliss ... and he's not regretting leaving behind his vigilante background.

Will he be able to maintain his happiness once he returns to vigilantism?
Mericle:That is really the central question of the season, especially with respect to him and Felicity. What we're really intrigued by doing is a couple things. One, seeing what Oliver and Felicity are like as a couple that works together and also has a relationship. What challenges does that present? We're really looking at this season as one where Oliver is stepping into the light, and we're going to have some jokes in the lair. We're not changing the tone of it too much, but making him a little funnier. He's happy and we want the show to reflect that. And the challenge of the season is going to be, 'Can he maintain that in the face of the darkness that is Starling City in the form of Damien Darhk (Neal McDonough)?'

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Is Damien Darhk what brings Oliver and Felicity back to Starling City?
Mericle:I can tell you it is Damien Darhk-related. It's partially related to Ray Palmer (Brandon Routh) and the power vacuum that's been left in the city after his unfortunate explosion at Palmer Tech. Part of it is the team of Black Canary (Katie Cassidy), Speedy (Willa Holland) and Dig (David Ramsey), who have stayed back in the city. He's passed the mantle onto them and they need his help. It's a confluence of factors. I can tease a little bit that Felicity is also deeply involved in that decision and has her own reasons.

What can you tell me about what's motivating Damien?
Mericle:We wanted to explore someone who really has no compunctions, who is just pure evil. He's a sociopath. He has no morals. He has no center at all. He doesn't really care about what he does in the name of pursing his personal agenda. In the past we've always had big bads like Malcolm Merlyn and Slade Wilson. Look at their stories and what they're trying to accomplish, and you could argue that they're the heroes of their own story. That is not going to be true with Damien. We wanted to explore what it was like for Oliver to go up against someone who is purely evil and is just a wacko, just a sociopath.

Will we see Black Canary and Speedy much more comfortable in their roles as heroes this season?
Mericle: Just by the virtue of the five months that go by, they are going to get really, really good at what they do and we're going to see them as a fully functioning team. And they're badass. We're going to advance them.

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We're alsogoing to meet Mr. Terrific (Echo Kellum) this season. How will he factor into the series?
Mericle:He's so funny and such a great actor and has such great fun onscreen chemistry with Felicity. We're really excited about that character because he's eventually going to become Mr. Terrific. We're loosely basing him on the comic book character, but really very much making him our own. We're excited he's going to be an addition to the LGBT cast that we already have in the form of Nyssa.

Will he be aware or become aware of Team Arrow?
Mericle:Early in the season we're going to make him aware of what Felicity does and her involvement with Team Arrow. But we're going to take a while before he identifies anyone beyond her, or knows who the Green Arrow is. Eventually, I think we'd really like to have him become part of the team, but we're going to piece that out over the season.

What can you say about Oliver officially becoming the Green Arrow?
Mericle: In keeping where Oliver is emotionally, we want him to take a slightly different tack as a superhero this season. We're going to maybe change the name. I'm not 100 percent sure about that. But he's definitely going to become a very different kind of superhero.

What role will H.I.V.E. play this season?
Mericle:Damien Darhk is involved with H.I.V.E., and that's one thing that we're very excited about. That name is going to really intrigue, in particular, Diggle in terms of a storyline that we set up back in Season 2 that his brother was killed by H.I.V.E. In addition to them playing a role with Damien in terms of his agenda with Starling City, we're going to get some closure, or at least explore what went on between Diggle, his brother and H.I.V.E. in the past.

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Will we see anyLegends of Tomorrowcharacters pop up this fall?
Mericle:We've already established that Ray is going to be a part of Legends of Tomorrow, so we will bring him back on Arrow. And also Sara Lance (Caity Lotz) is going to return to our show. And we're going to find new and inventive ways to spin them off into Legends.

What can we expect from Oliver's flashbacks this season?
Mericle:They're both going to be somewhat familiar and very surprising. And he's going to be going up against a big bad named Baron Reiter, who we've cast Jimmy Akingbola to play. Baron's going to be a very interesting influence on Oliver. He's a very formidable villain, but he's also very, very smart and very charming. And we're going to see Oliver go to his darkest place yet in the flashbacks this year.

Arrow premieres Wednesday at 8/7c on The CW.

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