At the end of May's season three finale, "Arrow" fans were shocked when Oliver Queen (Stephen Amell) and Felicity Smoak (Emily Bett Rickards) literally rode off into the sunset together as a couple -- and from what we've seen from the lovebirds during the show's hiatus, it's pretty clear that Oliver is still (finally) having fun, for literally the first time in three seasons.

But with a big bad named Damien Darhk (Neal McDonough) on the way and Starling City permanently in some sort of trouble, could that happiness possibly last?

"I know that Oliver Queen is certainly at peace at the beginning of the season," Amell told MTV News at San Diego Comic-Con. "He’s rested, happy, and domesticated... it’s interesting who is more at peace with the sort of domesticated set-up, the happily ever after set-up, so to speak, between the two of us.

"We get to see them as a couple working as a team," Rickards added. "Which is really interesting, and I think really good for our show, and good for them."

However, executive producer Marc Guggenheim reminded everybody that Darhk -- whom he referred to as the "heart of darkness" -- would surely bring down the mood, fast.

"With Deathstroke and with Ra’s and Malcom [Merlyn], those were always guys who were the heroes of their own story," Guggenheim explained. "They were guys who were doing the wrong thing for what they thought were the right reasons. This year, we wanted to do something different. We wanted a villain who was truly villainous; who didn’t care about morality in the way that the previous three big bads did. Damian is pure evil. He’s the heart of darkness."

"If something is going to lure Oliver and Felicity out of their light, happy place, it’s going to be the heart of darkness," Amell added with a laugh. "No, it’s interesting. It’s different this year too, where we’ve always taken the time to introduce our quote-unquote big bad, or the reveal of who the villain is. It’s not so much the case this year."

So get ready for a whole lot of Darhk-ness, early... but that doesn't necessarily mean that Team Arrow, who David Ramsey says will be a "well oiled machine" without Oliver and Felicity, can't have a little bit of fun while they fight heart of darkness crime.

"[Oliver] does crack a joke in episode one," Ramsey said. "He cracks a joke; it’s quite funny. Things are getting lighter! It’s a funny joke, and it’s also funny that he’s making a joke."

Sounds pretty great -- though according to Ramsey and his costar Willa Holland, who joked that the show would never "let anybody be happy," you can't ever expect "Arrow" to be as light and fancy-free as its hit spin-off series, "The Flash."

"We can’t be 'Flash,'" Ramsey explained. "'The Flash' is just so cute, and bright. We work over there too, and the set is brighter... and it’s funny, because when the characters come over to our world in the crossovers, they bring that with them. Like, they’re joking."

"We’re real dark," Katie Cassidy deadpanned.

Point taken, Cassidy: