Back at their base, Carl and Donut find Katia using her new makeup setup to imitate Hekla. Katia explains that her ability, Walk in Their Shoes, only changes the name over her head when the disguise is accurate enough, and her current version of Hekla is still below that threshold. Carl is alarmed to learn Katia spent her valuable upgrade coupons on a Makeup Table instead of Mordecai’s alchemy equipment, but he recognizes that the improved disguise system could still become tactically useful. Carl and Donut also give Katia armor looted from the assassin, which boosts her stats and, just as importantly, increases her mass. When Katia notices the skull over Donut’s head, Donut casually admits she killed a hostile crawler at the club, then leaves to train.

Carl spends an hour training Bare Knuckle and successfully raises it to level nine, while Donut trains Dodge to level seven. Carl then works at the engineering and sapper stations, using the Demolition Workshop interface for the first time to study explosives, inspect their stability, and dismantle fused hob-lobbers for useful parts. He repeatedly checks the cookbook in private while experimenting, and he learns enough to safely modify and combine explosive materials while standing at the bench. At the same time, Donut tries to learn how to ride Mongo using a saddle, but despite the magical strap holding her in place, Mongo resists and repeatedly throws her. The failed attempts make it clear that riding Mongo will require more than Donut’s claimed psychic bond.

After coordinating with Imani and Bautista, Carl, Donut, Katia, and Mongo move to a platform on the ochre line to prepare their train sabotage. Carl’s first priority is safety: he tests the rails with metal probes rigged with hob-lobber fuses and confirms that the raised third rail is live. To verify it further, Donut casts Clockwork Triplicate on Mongo and sends the duplicates onto the tracks; one explodes on contact with the third rail, and the other is crushed by an arriving train. While Donut kills two skunk-like mobs that spill from the car, Carl spray-paints a large X on the train so Meadow Lark and Bautista’s crew will know it is the last safe train before the sabotage begins.

With the rail hazard confirmed, Carl places two homemade land mines on the track, choosing a simple derailment plan over a more elaborate ramp because he lacks precise measurements. The mines, which the system calls Jelly Bombs, are designed to detonate on impact and throw shrapnel hard enough to knock a train off the rails, though Carl worries about accidentally killing the engineer or triggering the explosives too early. Once the charges are set, the group retreats to the station stairs and prepares to flee either into a safe room or onto another line if the attack goes wrong. Carl notices the nearby entrance to Club Vanquisher and a hostile ram-headed cleric watching them, then receives a message from Elle saying her group explored one of the five-station branches, fought three neighborhood bosses, and found a borough boss named Miss Krakaren, whom Imani believes Carl knows. As the ground begins to rumble with the next train’s approach, the team waits for the derailment attempt to begin.