What You Need To Remember About Infinity Train Season 4

Infinity Train's fourth season (or "Book" as the show calls them) is about to pull into the station, with its premiere date set for April 15, 2021. This will mark its final season on HBO Max, although creator Owen Dennis has said that he has plans for many more seasons of stories. For now, Book 4 will be the closest thing fans have to closure for one of the oddest cartoons on television. 

The end of this iteration of Infinity Train has to be disappointing for fans who wanted to learn the mysteries that have been the foundation of the show. Infinity Train is told anthology-style, with each season focusing on a mostly new group of characters. Although a handful of characters do appear on multiple seasons, the closest thing to a recurring character is the Infinity Train itself — a supernatural train that never stops and has an endless number of cars, each one with a different theme or style. Characters do attempt to explore the surreal train, but the real reason they're on the Infinity Train is that they all have personal baggage or issues to figure out.

The Book 4 trailer introduced the three new main characters. Ryan and Min-Gi are best friends who want to be rock stars, and Kez is their guide, a talking concierge bell. While their story will be new, Dennis also said this season will dig into the Infinity Train's history and lore.

Here's what you need to remember about the Infinity Train heading into Book 4.

Every character who arrives on the Infinity Train experiences another strange phenomenon: neon green letters appear somewhere on their body, usually on their hands and arms. Book 3 finally revealed what those numbers actually mean. Anyone who finds themselves on the Infinity Train is there for a reason: they have some sort of personal problem they must overcome. Their number goes up or down depending on whether they make progress toward resolving that problem or not. 

Most significantly, Ryan and Min-Gi both have the same number on their hands, 208. As Kez points out, that's never happened on the train before. While it could be an error on the train's part, more likely it means their problem is the same — or connected in some way. HBO Max's official synopsis for Book 4 already indicated that Ryan and Min-Gi had a falling out just before boarding the train, so the state of their friendship would be a good bet for the reason why they're there. 

Based on their clothing, technology, and other details, Ryan and Min-Gi are most likely boarding the train in the late 1970s/early 1980s. That's around the same time that Amelia Hughes Timmens first boarded the train, so she most likely will be on the train at the same time as the two friends.

Amelia (Lena Headey) was a major character in both Books 1 and 3. When she initially boarded the train, she asked its original conductor, One-One, to construct a car specifically for her that contained her lifelong love, Alrick, who died tragically. When One-One refused, Amelia angrily overthrew him and took control of the train. For the next three decades, Amelia attempted to reform the train to suit her whims and possibly warped the way it works, making it more dangerous for future travelers. By Book 3, Amelia has seen the error of her ways and is trying to undo the damage. But if Ryan and Min-Gi do encounter her, they would be meeting the earlier version of Amelia, who would presumably be more of an antagonist.

But that's if Amelia appears at all. On Infinity Train, you just never know.