Floor 4 · The Iron Tangle

The fourth floor of the World Dungeon, called the Iron Tangle: a subterranean web of train lines and stations built as a puzzle. Colored-line trains only climb their line, stairwell stations are held by ghouls and bosses, and crawlers may not descend early. Some 389,441 crawlers arrived. The floor lasted ten days and ended in a self-destruct sequence and a final run into the Abyss.

1. Carl, Donut, Mongo and Katia arrive in the last car of a moving Red Line train, among 389,441 crawlers entering the floor. source
2. Carl causes his first derailment by crashing an Ochre Line train. source
3. Carl hijacks the Nightmare Express. source
4. Carl rides the Nightmare Express to station 436, finds the Abyss, and learns that the souvenir hats carry crawlers through the end-of-line portals. source
5. The trains stop running and ghouls overrun the network, stranding hundreds of crawlers at the end of the line. source
6. The Royal Court uses repair carts fitted with portal scoops to rescue just over 1,400 stranded crawlers. source
7. Katia and Mordecai work out that the floor's track layout is a scaled-down map of the galaxy, with the Abyss at its centre. source
8. With a day left, management declares the system broken, blames the Krakaren and starts a self-destruct sequence that sends everyone through the escape tunnels toward the stairwells. source
9. Carl summons Grull and sends him by portal cart into Trainyard E, where Grull kills the Station Mimic. source
10. Fire Brandy drives the bomb-laden Nightmare Express into the Abyss, the explosions overload the ghoul generators, and the crawlers holding station 36 descend to the Fifth Floor. source
11. Of the 389,441 crawlers who arrived on the floor, just over 178,000 reach the Fifth Floor; tens of thousands die in its last hours. source
12. The Abyss explosion is revealed to have killed every wall monitor in the pit. source
13. The same blast is revealed to have detonated the soul crystals across the Tangle, opening the floor so crawlers could escape. source
14. The floor's train employees are revealed to have been fully brainwashed, which let the Royal Court recruit a few of them when the illusion broke. source

Located in

Trainyard, Abyss Station, Desperado Club, Club Vanquisher

Travels to

Floor 3 · The Over City, Floor 5 · The Bubbles, Carl, Princess Donut, Li Na, Prepotente

Home of

Trainyard, Abyss Station, Gore-Gore