Critical Role's Liam O'Brien says the new season of the Amazon-backed 'Vox Machina' series is going to break fans' hearts

• The third season of the Amazon-backed animated series "The Legend of Vox Machina" will premiere on October 3.
• The new trailer for the series teases flashy fights and some huge romance moments.

The wait for the new season of Critical Role's Amazon-backed series, "The Legend of Vox Machina," is almost over.

What once started as a group of nerds playing "Dungeons & Dragons" has morphed into a company that does live shows at London's Wembley Arena and makes its own board games. They're also cooking up new episodes of two Amazon-backed animation series based on the eight-member cast's long-running "Dungeons & Dragons" campaigns.

And on Wednesday, Prime Video and Critical Role released the official trailer for "The Legend of Vox Machina's" third season. In this jam-packed preview, the adventurers known as Vox Machina travel to hell and back — quite literally — to find a way to save their world of Exandria.

And for fans who want a little bit of romance, the trailer also teases a kiss — and what looks like definitive progress in the love story between the roguish Vax'ildan, voiced by CR cofounder Liam O'Brien, and the druid Keyleth, played by creative director Marisha Ray.

The first three episodes of "The Legend of Vox Machina" will be available on Prime Video on October 3. This season has twelve episodes.

In the last month, BI spoke to two of Critical Role's main cast members and pressed them on what fans might see in the next season of "The Legend of Vox Machina."

Matthew Mercer, CR's chief creative officer, told BI in early August that stepping back into the Vox Machina adventuring party — the "D&D" characters they first started streaming on Twitch with — was an emotional experience.

"We get to take these stories, and these characters and these worlds that we played together in, that forged our friendships, and now we get to revisit them and see them realized in one of our favorite mediums of storytelling," Mercer said.

"And it gets even more intense with every season," he added. "Season three is wild."

O'Brien, meanwhile, says fans should "strap in" for some heartbreaking moments because season three is "going to hurt real bad."

He added that production for the "Mighty Nein" animated series — also to be hosted on Prime Video and based on Critical Role's second major "Dungeons & Dragons" campaign — is well underway.

"It's so different than 'Vox Machina.' It definitely has its unique soul," O'Brien said of the "Mighty Nein" series. "We're starting to see the locations, and the character designs are being fine-tuned, and it's a whole different ball game."