Burn what?
That was a good question. Theus understood machinery far better than anyone in this era, yet even on Blue Star, there were only a few kinds of things used as industrial fuel.
First came solid fuels: coal, firewood, straw, and the like. Humans had used those for thousands of years.
Then there were petroleum and natural gas, including various alcohols and alkanes. They were the lifeblood of modern society; everything from speeding cars to rockets relied on their combustion.
Beyond that came nuclear fission and fusion—from uranium to gases, xenon, and helium-3. Their brilliant radiation was also the radiance of civilization.
So what, exactly, counted as mortal fire?
In this world, mortals naturally stood in contrast to Transcendence. Thinking of how Pollution had burned obediently and steadily within that evil god's Steam Engine before... perhaps the Mechanical Cathedral was also making use of Pollution?
Now that was interesting.
"Are you sure the Mechanical Cathedral has no path to Transcendence, and no Transcendents?"
Chloe considered for a moment before speaking. "I think you may have some misunderstandings about the Mechanical Cathedral... The Mechanical Cathedral truly has no path to Transcendence; it isn't a Transcendent organization. But there are definitely Transcendents among them."
As she spoke, Chloe rubbed her eyes, then raised a brass holy emblem. "I'm one of them."
The breathing of those around them stalled in rhythm with the trembling steam pipes. Gazes fell upon Chloe, and the brass emblem swayed gently in the firelight of the Steam Engine. Theus's eyelid twitched.
"You're with the Mechanical Cathedral too?"
He took the holy emblem from Chloe's hand and inspected it closely.
Dark golden ripples flowed across the surface of the brass emblem. Between the steam-gear patterns etched along its edges lay dark red verdigris resembling veins, and beneath the