A jet-black, coal-fired steam train hauling caged giant monsters in a figure-eight loop to the Abyss — hijacked by Carl.
The Nightmare Express is a named loop-train of The Iron Tangle, a jet-black steam locomotive marked "666" that runs a figure-eight through several transfer stations up to the end-of-line Abyss Station 436. It hauls roughly forty cars — freight and open-topped livestock cages holding fourteen giant monsters — with entry only at the caboose or a front passenger car, and a war mage lurking aboard. After a failed rooftop plan, Carl clears it by casting Protective Shell in the tunnel ahead, then rides the cowcatcher and hijacks the runaway engine with Fire Brandy's help — killing every monster (three of them bosses) and stealing the train outright.
A jet-black, coal-fired steam locomotive with a low wedge cowcatcher and '666' emblazoned in red on its boiler, pulling ~40 cars including open-topped cages of thrashing giant monsters, wreathed in steam.
A key named loop-train and Carl's hijacked route toward the Abyss and the stairwells.
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