The Backrooms

Yellow sat back in his office chair, sipping a can of sprite. Ever since he'd gotten promoted to Manager of Construction, everything was so much better. He got soda, he got access to Hermes devices…

…and there was an endless stream of business proposals.

"Come in," he said. The door opened, and Michael ████ entered, carrying some sort of easel. Yellow groaned. Every week, Mike came to his office with some ridiculous plan for making The Backrooms easier to navigate. Last time, it was a giant road map of every level. Every level. What was it going to be today…

"Yellow! You've got to see this!" Mike yelled. He set down his easel and took off the veil. "Are those… train tracks?" Yellow asked. This was unexpected.

"Yes they are!" Mike proclaimed. "You know how you have to walk for, like, 100 miles in Level 9 to reach Level 11? Well, what if you didn't have to walk all that way? We could construct a train line that travels between levels! It would save so much time!"

Yellow sighed and put his face in his hands, “Mike, we’ve gone over this before. Where would we get the fuel?”

Instead of deflating like he usually did, Mike’s grin only grew wider. Yellow groaned internally, sensing he’d walked right into yet another one of Mike’s brainstorms.

Mike reached down and pulled a rolled up paper out of his bag. He flattened it over Yellow’s desk, knocking Yellow’s paperwork to the ground in the process and spilling his drink. Pointing to the sketch on the paper, Mike explained, “We can reuse the same fuel!”

Yellow looked at Mike like he was nuts, “How on Earth would you expect to be able to do that? Perpetual motion is impossible, you can’t reuse your fuel.”

Mike corrected Yellow, “How in the Backrooms would I expect to do that, you mean. We’re not on Earth, and the rules are different here.”

Mike pointed to the diagram of the steam engine where there was marked what appeared to be an additional boiler. “We can use Blackfire to convert the ash back into fuel.”

Yellow stared at Mike, before saying very slowly, “Blackfire is fire in reverse, it doesn’t make heat, it makes cold. Fire and Blackfire cancel each other’s effects out so the reaction is useless.”

Mike countered, “That’s why the Blackfire is in this condenser, separate from the boiler. It can absorb heat from the environment and steam, and then transport that energy in the form of fuel to the boiler where it gets converted back into heat, but this time it’s in the boiler where the engine can use it. It also condenses the steam and recycles the smoke so the engine is a closed loop with no waste.”

Yellow started to counter but paused. That could work, actually. He leaned forward. A train… going from Level 9 to Level 11… He sat there in thought for a bit, then finally said "what if we make it a monorail?"
Mike’s grin grew so wide it practically split his face.