Fans of "Arrow" can expect to see a new lighter side of Oliver Queen when Season 3 of The CW series kicks off next month.

In the Season 3 finale, Oliver decided to hang up his hood and leave Starling City in order to start a new life with his girlfriend, Felicity. However, Oliver's newfound peace and happiness will be interrupted in the Season 4 premiere when he is called back to Starling City to face off with a villain of "pure evil" named Damien Darhk.

During an interview with TVLine, executive producer Wendy Mericle elaborated about why Stephen Amell's character is summons to return to his hometown, which has been renamed to Star City.

"The city has declined drastically despite the best efforts of Dig, Speedy and Black Canary," said Mericle speaking about the season premiere. "And with the arrival of Damien Darhk (Justified's Neal McDonough) on the scene, it's obviously big stakes."

Executive producer Marc Guggenheim also opened up about Oliver's transformation into the Green Arrow and the new season's lighter tone.

"Ever since Slade Wilson [Manu Bennett] came to town around [season 2, episode 15], the show has been on this very, very dark path, leading to Sara's [Caity Lotz] death and the culmination of season 3," he told Entertainment Weekly. "Our goal was to return the show more in the tone of the first season-and-a-half."

As a result, viewers will see a much happier and carefree Oliver enjoying suburban life with Emily Bett Rickards' Felicity.

"It still feels like Arrow, but at the same time, Oliver's got a new outlook on life," Guggenheim said. "We're driving conflict to the show in ways that we never would have in the first three years. So it still feels like Arrow, but it's a different take on the show."

The EP added that "We played him as a guy who was returning home from war with PTSD for the first three years. Now he's put those demons to rest, or so he thinks, and there's a lightness to him as a result of all the things he learned last year."

Oliver "has more faith in humanity than he did in the past," Mericle added. "It's less about erasing his father's legacy and more about establishing his."

Although Oliver is petitioned to return to Star City, not all members of Team Arrow will be as welcoming about his homecoming. Diggle (David Ramsey), in particular, is still "frosty" toward his "brother,"while Quentin still is not thrilled with the masked vigilantes yet has come to see them "as a necessary evil," Mericle said.

"[Diggle] was the one who was most angered over Oliver's choices at the end of season 3," Guggenheim says. "And he's certainly the one who's most against Oliver returning and him being forced to work with Oliver."

However, Oliver won't be the only person to undergo a major transition in the new season. Viewers will also see a different side of Malcolm Merlyn now that he is no longer in hiding and has been crowned as the Head of the Demon in the League of Assassins following Ra's al Ghul's death. Meryln will play a role in resurrecting Sara Lance from the dead. Fans will also see him in his role as Thea Queen's father, although Guggenheim warned that he is far from the perfect parent.

"The best way to put it is its father knows worst," said the EP to EW. "Malcolm comes into the story very much more in the role of Thea's father than in the role of the Head of the League of Assassins. It's so much fun to play with Malcolm as dad because his choices are just very unusual. Much to the chagrin of Thea, he doesn't handle things the way a typical father would."

Laurel Lance, aka the Black Canary, will also play a role in bringing Oliver back into the Team Arrow and her sister, Sara, back to life. According to Guggenheim, the process of resurrecting Caity Lotz's character will tedious and emotional.

"[Sara's resurrection] very much comes about because of decisions that Laurel makes and choices that Laurel will then have to live with ... The episodes dealing with Sara's return are amongst probably the heaviest material that we've had for Laurel. We're using Sara's return to really get underneath not just Laurel as a person, but the relationship that she has with Thea and the friendship that she has with Oliver."

"Arrow" Season 4 will premiere on Oct. 7.