After clearing the remaining monsters in cars three and four, Carl uses his engineering bench to deploy improvised barricades: heavy gangway chocks and door wedges meant to isolate a car during station stops. At station 84, the setup is tested against level-22 pollyslogs. The fishlike monsters become violent only when they realize they cannot board, and the train doors sever and crush them as they cling to the barricades. The defenses work imperfectly but well enough to keep Carl, Donut, Katia, and Mongo from being overwhelmed.

With a few minutes before the next stop, the group advances into car five, an employee-only break room. There they meet Vernon, the Yellow Line conductor, a drunken dwarf who explains that monsters obey the rule not to enter his car. When two janitor ghouls pass through without attacking, Carl realizes Vernon is telling the truth. Donut’s royal act makes Vernon cooperative, and Carl begins questioning him about the line, hoping to understand how the Tangle works and where the train goes after its final station.

Vernon reveals crucial information: the Yellow Line runs to station 435, but after that his memory blanks and he always finds himself back at station 10, the yard. He does not believe he is fully in a time loop, because his hunger, injuries, and pocketed items persist between cycles, while objects left on the train reset. Vernon proves this by showing a scar, duplicate drawings of his wife, and gold coins that multiply because he carried them with him when the train reset. He also explains that monsters board and disembark on a regular five-stop pattern, that some transfer stations connect to many other colored lines, that the whole ride from station 11 to 435 takes three days, and that an engineer almost never leaves the engine car unless there is a derailment.

Carl realizes Vernon is an invaluable source of map and station knowledge, so Katia stays behind to relay Vernon’s information to Mordecai while Carl, Donut, and Mongo investigate car ten, the porter car, during an empty stretch between monster stops. There they discover the Yellow Line reward room and meet Pierre, a noncombatant Grapple porter. Each crawler may claim one numbered suitcase, so Carl takes suitcase one and Donut takes suitcase eight. Back in the conductor’s room, Carl opens his own case and finds ordinary luggage containing clothing, travel brochures, two mana potions, and an invisibility potion, proving the prizes are hidden inside normal-looking baggage.

When Carl starts opening Donut’s suitcase, a warning appears from his Find Traps skill just as flaming ants pour out. The suitcase is a trap monster container, and the fire ants ignite Vernon’s papers, spread through the room in impossible numbers, and trigger an explosion when Vernon’s moonshine catches fire. Carl, Donut, Katia, and Mongo are burned and forced to flee forward through the train. Vernon is engulfed and killed. As the train stands at station 116, the group escapes onto the platform moments before the doors close, leaving the newly boarded rabbitlike monsters to be consumed by the spreading fire as the train pulls away. The chapter ends with the group stranded off the train after losing both Vernon and a major source of live guidance.