'The 100' season 4 spoilers, updates: Octavia loses hope? Chai Romruen latest to join upcoming season's cast

It has been confirmed that "The 100's" arc for season 4 would revolve around a nuclear disaster. However, apart from that, viewers would see several new faces joining the show when it returns for its fourth run.

To recap, the season 3 finale saw the downfall of the City of Light. Concurrent with it, some grounders and Arkers were seen doing vile things while under the mind control of villainous artificial intelligence ALIE (Erica Cerra).

It was earlier announced that two new grounders â€“ Hugo and Kenza – would join the fray. It was even teased that Hugo would abhor ALIE for making a monster out of him while under her control. Now, it looks like another Grounder is set to debut in the upcoming season.

Apparently, "Mako Mermaids" alum Chai Romruen has been cast as Ilan, a Grounder haunted by the things he did while under ALIE's manipulative powers. During this year's San Diego Comic-Con, "The 100's" executive producer Jason Rothenberg teased the addition of an important character.

"We definitely are going to meet (or get to know) someone from [what's] called Trishanakru, which is like 'tree shine'. It's the Glow Forest clan," Rothenberg told Enstarz.

According to Rothenberg, this important character would be introduced in the season 4 premiere and would "play a big role in the season."

Meanwhile, apart from the nuclear disaster that many of the Sky crew would face, some of the characters would likewise be going through individual problems. Octavia Blake, the character portrayed by Marie Avgeropoulos, is no exception.

Speaking to Showbiz Junkies at the SDCC, Avgeropoulos said while the other characters are holding out hope for their future, such would not be the case for Octavia. She also teased that Octavia would be part of a new group in season 4.

"It's going to be a really emotional journey for Octavia. She takes a really dark turn into some pretty nasty pastures," she said. "You know, Octavia thought killing Pike would sort of band-aid that wound in her heart. It doesn't. It actually triggers something even more disappointing because she thought it would fix that and make it all better. She is going to do what she does best next season, and that's killing people. She doesn't enjoy or take pleasure out of it; she just knows that's her skill set."

Will Octavia's new group help her for the better or will they harm her? Will she totally say goodbye to the Sky crew?

The answers would be revealed when "The 100" season 4 premieres in early 2017. In the meantime, keep coming back for more updates about the show.