Outside her window, the first tremor of the morning shift change rumbled from the city’s subway. But Elara felt a deeper vibration, rising from the soles of her feet.

The seismic data showed a massive, dome-shaped anomaly two kilometers beneath the surface. It wasn't a cave or a magma pocket. The density scans suggested something dense, geometric, and impossibly old. And in the center of that anomaly, the survey had detected a faint, rhythmic vibration—a pulse of exactly 0.3 hertz. The frequency of a turning page.

She printed one page. Just one: the loop between Page 12 and 47. The ink was warm when it came out of the laserjet.

Each "page" was a high-resolution scan of a hand-drawn geological cross-section, but the strata weren't horizontal. They folded in on themselves like a Möbius strip. Layers of basalt kissed layers of future chalk. Flint had drawn arrows, not pointing up or down, but through the page. He had annotated the margins with a code Elara now realized was a rudimentary hyperlink—pen-and-ink links that jumped from one PDF page to another, creating a loop.