The basic premise of Cartoon Network—now HBO Max’s—animated anthology series Infinity Train is deceptively simple: Kids struggling with issues in their lives find themselves whisked away by a magical, endlessly sprawling locomotive, where a series of strangely themed train cars help them deal with their aforementioned interpersonal problems. Journeying with an infinite universe’s array of goofball robots and talking animal companions, the kids re-learn how to open up, stand up for the people they care about, and accept that they can’t control everything in their lives. In the end, they pass an emotional milestone, come to terms with their own inner demons—and, often, some actual, highly dangerous monsters—and finally get to go home.

All well and good. But what happens when someone doesn’t want to—or isn’t able to—perform that kind of growth? What happens to someone trapped in a reality designed to help them become a better person… and they’re so invested in their misery that they find themselves incapable of change?

That’s the question raised by the show’s third season (chapter, book, etc.), which pulls the wonderful third-season TV trick of taking a world that’s now been fully, thoroughly established, and pushing at the edges of it to see what else can be discovered. Here, that means delving deeper into the origins and philosophy of “The Apex,” a group originally encountered back in the show’s second season. Made up of kids who’ve rejected the Train’s overall message, The Apex are driven by two beliefs: That the creatures encountered in the Train’s various cars, who they dub “Nulls,” aren’t real people—and can thus be dealt with as one pleases. And second, that the only goal in life is to get your number (i.e., the Train’s countdown to personal epiphany, tattooed on every passenger’s arm) as high as humanly possible, often by breaking or killing any Nulls they can get their hands on. These highly destructive Lost Boys and Girls thus spend their days hanging out in a trashed shopping mall (or, at least, a train car that looks like one) and launching raids on other cars under the guidance of their leaders, future Proud Boy wannabe Simon (Kyle McCarley), and charismatic manipulator Grace (Kirby Howell-Baptiste).