Book Three of animated sci-fi series Infinity Train rolls into the streaming station in just a few weeks.

During a Comic-Con@Home panel for the show, creators and writers announced the next season would hit HBO Max on August 13.

The third season of Infinity Train, subtitled Cult of the Conductor, will bring together new and old characters for a new car-hopping adventure. The panel debuted the first trailer for Book Three. Check it out below to get your first look of new passengers Hazel and Tuba, and the return of Grace and Simon. (Trailer begins at the 39 minute mark.)

Infinity Train is a sci-fi animated series in which each car of the mysterious train is its own pocket universe. Passengers wake up on the train with a number on their palm, which moves up or down based on their actions. They have to get it down to zero to make it off the train.

A look at the Book Three characters

When Grace and Simon turned up in Book Two, fans predicted they would make a comeback.

“And they were right! It made us feel really unoriginal,” joked writer Lindsay Katai.

Grace and Simon lead an anarchist-type group on the train, believing they need to fight back against it. Instead of making their numbers go down, they take pride in getting them to increase exponentially. In Book Two, MT and Jesse briefly consider joining their gang, but end up moving on.

In Book Three, Grace and Simon stumble upon a new passenger while exploring the train. Her name is Hazel. She’s the youngest passenger the show has focused on, which adds a new dynamic to the story.

“Everybody’s gonna love Hazel,” said Katai. “She’s so flippin’ cute!”

By the time Hazel meets up with Grace and Simon, she’s already befriended Tuba, a giant Tuba-carrying ape. But Tuba’s a part of the train, which makes him an enemy in Grace and Simon’s eyes.

Grace, Hazel, Simon, and Tuba in Infinity Train Book 3

Overall, the first look at Book Three demonstrates Infinity Train will continue to explore new depths.

Watch the full panel to learn more about the show’s writing and animation process.

Check back with That Hashtag Show for more of the latest news out of Comic-Con@Home.