Lanthornia is a planar stack set beside Alaria's own, one of the stranger stacks beyond the home stack rather than a layer within it. There, Aether is the ordinary source of energy, the primary meta-fluid of the place, doing the everyday work that water and weather do here. None of that carries over. Aether is not one of the four sources of Alarian magic and it is not a fifth source bolted on; on this side of the gap it is simply foreign, a substance from the next stack over that the home world has no use for and cannot even feel.
What Alaria knows of Lanthornia, it knows the way a shore knows a storm it never saw: by the wreckage left on the sand. No ordinary passage runs between the two stacks, and nothing native to Alaria has gone there and come back to report. The world has the debris, and from the debris it has guessed at the rest.
The eruption
An eruption tore through Lanthornia and threw a great mass of its substance clear of the stack, Aether and the gray-blue stone Lanthornium together and in bulk, and all of it came to rest on Alaria. The Aether settled into the air and stayed, inert and invisible, a meta-fluid hanging through the whole sky with nothing in the native world able to grip it. The Lanthornium came down as scattered stone. That one event is the root of Alaria's entire sky-industry: every Aether engine and every hull that floats on a struck plate traces back to what a single eruption on a neighbouring stack happened to spill here. None of it is a remnant of the lost aetherial height. It is younger than that, and stranger — off-world matter that simply landed, not a craft Alaria once held and forgot.
A people grown to the accident
The deposit reshaped who could live off the sky. Aether hangs everywhere it fell, but drawing it down takes a sensitivity nothing in Alaria was born holding, and the goblin aether-tappers are the answer the world grew to it. Their gift came up in the generations after the eruption seeded the substance across the sky, which makes them a new thing rather than an old one. They are no relic of a lost age. They are a people shaped by a foreign accident, fitted to a fuel that had fallen out of another stack before any of them drew breath, and the whole sky-trade now leans on that single adaptation. See race-goblin-aether-tapper.md.