Before history, the First Boiler fell from the night sky and buried itself beneath the continent. Three mortal visionaries discovered its pressure chambers: Brammel Pike heard the cries of workers trapped in its furnace, Ketsur Vey saw every possible future reflected in its gauges, and Orshad-under-Glass found a sealed vault of impossible wealth. Their contact transformed them into gods, but the awakening also divided the world into rails, roads, and locked doors.

The world is a vast engine built around a buried star called the First Boiler. Its pressure feeds three divine mechanisms: the communal furnace tended by Brammel Pike, the probability-wheel guarded by Ketsur Vey, and the sealed pressure-vault claimed by Orshad-under-Glass. Every miracle releases steam from the First Boiler, and every act of worship either repairs, redirects, or dangerously increases the pressure.

The religion is called the Engine Faith, though its congregations are decentralized and often fiercely argumentative. Brammel Pike's adherents organize as Guildchapters, practical temples that double as workshops, hospitals, union halls, and fire brigades. Ketsur Vey's followers form loose Circles of the Unfixed, with no permanent hierarchy and no shrine kept in the same place for long. Orshad-under-Glass is served by Charter Houses, legally recognized banks, mining concerns, courts, and private chapels where bargains are witnessed. Mixed congregations are common in frontier settlements, but every major civic decision eventually becomes a theological dispute among Guildchapters, Circles, and Charter Houses.

The gods are visibly involved in mortal affairs. Their agents ride trains, appear in courtrooms, haunt mining camps, bless workshops, manipulate elections, and answer prayers with physical signs. Divine power is practical rather than distant: a boiler may ignite, a wanted poster may change its wording, or a contract may develop a second line of text. Clerics and champions commonly serve one deity while negotiating with the other two, and religious disputes often become labor conflicts, legal battles, railroad wars, or frontier expeditions.

The dead arrive at the Last Junction, where three rails depart into three divine territories. Ketsur Vey weighs the memories clinging to the soul; Brammel Pike oils the soul's old wounds and sends it onward; and Orshad-under-Glass offers one final bargain to return, provided the dead can name a living debt worth paying. Souls that refuse all three become whistle-wraiths, haunting abandoned rail lines.