A few surprising characters are set to be back in Arrow Season 8. The show is proving the final season is going to be bigger than expected with the returning former cast members that helped to shape the series from the very beginning.

Aside from Adrian Chase (Josh Segarra) and Tommy Merlyn (Colin Donnell), Oliver's (Stephen Amell) mom, Moira (Susanna Thompson), and archenemy, Malcolm Merlyn (John Barrowman), will make a return. Also, it looks like it will be a family reunion with the comeback of Ollie's sister, Thea (Willa Holland). So, how will this happen?

According to IGN, showrunner Beth Schwartz can't also explain how these characters manage to return. However, in the new season photo, it seems to suggest Oliver will be visiting an alternate Earth, where his mother fell in love with Malcolm instead of his father, Robert Queen (Jamey Sheridan). However, it remains to be seen if this is what is really going to happen in the premiere episode.

"All I can say is that it's something we've never done on our show before," Schwartz said about Arrow Season 8. "We're going to see a lot of familiar faces in a different way than we've done on the show before."

However, Schwartz revealed it was a priority to bring back Thompson and Barrowman in the last and final season, given that they both played significant roles in the early seasons. She went on to explain they wanted to make everyone, who made the show a success, return.

One of the familiar faces returning is Thea, who appeared in the earliest episodes of Season 1. She has been one of the strongest characters in the series. She is known as the "emotionally-distraught party girl sister" of Oliver that turned into a superhero Speedy in Season 6. The returning characters will never be complete without the original ones like Thea.

Green Arrow TV noted Thea might be seen on Arrow Season 8 Episode 3, titled "Leap of Faith," which is set to be out on Oct. 29. However, it has yet to be revealed how many episodes she will make be seen. Will she play a big role in the much-awaited Crisis on Infinite Earths crossover since it will be the end of her brother?

"We are thrilled to have Willa back in our final season," Schwartz said about her return. Holland left the show in Season 6. She once again made an appearance on its 150th episode but never returned since. However, she was seen as a talking head in a documentary about Oliver in Season 7.

As Thea is only the remaining character that knows Oliver before he transformed and an immediate family member, she is an integral part of his story. Hopefully, The CW will give her a proper ending when Arrow Season 8 hits the small screens on Tuesday, Oct. 15, at 9 p.m.