Infinity Train Season 4 - What We Know So Far

For fans of unique adult-oriented animated series, HBO Max's recent announcement of the return of Infinity Train is great news. For those who aren't familiar with one of the strangest cartoons on television, Infinity Train, like the name suggests, is about a mysterious, constantly running train with an infinite number of cars, each one with a different theme. While the Infinity Train is populated by many flawed characters trying to make sense of their surroundings, the real star of the show is the train itself. Each of the first three seasons have featured a different main character learning the secrets of the Infinity Train and trying to find their way home again, but the train rolls on.

After Cartoon Network aired the pilot, the fan response was so strong that it gave creator Owen Dennis and his team a rare degree of creative freedom. "[We can] do some things content-wise that other shows might not normally be able to do, simply because Infinity Train already has a fanbase," Dennis said on Reddit. There are few shows that can offer surprises on a weekly basis as well as Infinity Train does. Both fans and characters never quite know what's going to be in the next car, and that's part of the fun. 

Surprises are a big part of Infinity Train's appeal, so some details about the upcoming fourth season are still a mystery, but here's everything we know so far.

HBO Max's tweet confirmed that there would be a new season of Infinity Train but didn't indicate when fans can expect to tune in for Book Four, which is Infinity Train lingo for "Season Four." In its tweet on Feb. 17, 2021, HBO Max simply said that Book Four would be "Coming Soon."

But based on Infinity Train's past release schedule, that should be sometime in early March. Infinity Train seasons usually debut about seven months after the previous season's finale, and Book Three's finale was on Aug. 27, 2020, putting early March at seven months out. Infinity Train's season premieres typically come about three to five weeks after Cartoon Network announces them. Cartoon Network announced Book Two in early December 2019 before that season premiered on Jan. 6, 2020. Book Three was announced on Jul. 6, 2020, and it premiered on Aug. 13, 2020.

That would put Book Four's premiere date at Mar. 10, 2021 at the earliest, but possibly one to two weeks after that.

Your guess is as good as ours. While Infinity Train does have an overarching plot about the mysteries of the train and its origins, each season usually features a different main character with new issues to work through. Longtime voiceover artist Ashley Johnson, who played the show's "main character," Tulip, is the only main cast member who returned for a second season. But Book Two technically dealt with a "mirror" version of Tulip, who had her own separate personal problems and wasn't the same character. 

Book Three did leave the story of its main character, Grace (Kirby Howell-Baptiste), somewhat open-ended. Grace is the leader of the Apex, a cult-like group made up of child scavengers on the train. While the Apex used to be focused on mere survival, Book Three ended with Grace reforming the group and dedicating it to helping its members solve their personal issues, which would allow them to leave the train. But again, Book Four could pick up with a new character entirely. 

The only people who know for sure are Owen Dennis and the folks making the show.

Like casting details, plot details for Infinity Train Book Four are scarce. HBO Max's tweet about it also included a 15-second teaser trailer for Book Four, but it was typically mysterious. The trailer shows a blurry train moving past the screen while two garbled voices speak over it. Captions on the Instagram video don't offer much more clarity beyond one of the voices asking, "Where are we?" But it's a teaser trailer and not meant to reveal anything significant.

Book Three ended with a big reveal about the meaning behind the strange, glowing green numbers that appear on the Infinity Train's residents. Grace discovered that people become stuck on the train when they have personal demons to sort through. Their numbers either go up or down depending on whether they make progress or backslide. Even if Grace doesn't come back, this information is a game-changer and will likely lead to more revelations about where the Infinity Train came from.

Book Four will no doubt explore the themes of existentialism and redemption that are familiar from the last three seasons. Whatever the season is actually about, it will no doubt inspire lots and lots of fan theories.