Sealed into a boss arena with half-visible walls, then flattened by a god: buckled ground, slagged trains, and a bisected city boss.
Carl arrives by falling through a portal into it and immediately discovers it is no longer open ground. Princess Donut reports that the trainyard walls have magically come back, only half visible, like the boss battles on the first floor — a minion went in and could not come back out, so you can enter but not leave. Every one of the yard's named-train portals, the ones the trains use to return to the loop, is switched off.
What happens inside over the next few minutes: the Station Mimic's tongue splits train cars and craters the ground; Grull erupts out of a mantaur amid exploding trains, rocks and metal and rises until his head is halfway to the ceiling; his axe cleaves the earth into meteor craters and the mimic into halves; his heat breath turns trains and awnings into slag along whole lines; and a rolling train car flattens Carl. Afterward the The Nightmare Express chugs in and stops a few tracks over, Tizquick gawks out of the window at the remains, and a group of wide-eyed crawlers climbs out of a crashed train car and runs from the scene, not trusting that it is over.
A cratered cavern of buckled track, derailed and melted trains, half-visible glowing arena walls, and a bisected mountain of mimic flesh.
A trainyard converted into a sealed arena for a televised death match.