“Stupid,” he muttered. “Stupid, stupid.” He wasn’t a speleologist. He was a surveyor . His job was to measure things that already existed, not chase rumors of lost Roman marble quarries.

Non-opaque.

I cannot directly generate a story from the contents of that specific PDF manual, since I don’t have live access to your local file or its internal pages. However, I can absolutely write an total station manual’s themes: precision, surveying, hidden measurements, and the quirks of old-school gear.

But the manual—the dog-eared, coffee-stained Leica TCR 303/305/307 User Manual —had said something on page 47 that now burned in his pocket: “In Reflectorless Mode (Standard deviation: 3mm + 2ppm), the instrument can measure surfaces previously considered optically unstable. Trust the EDM, not your eyes.”

He aimed again. Pressed .

Marco’s blood cooled. The laser wasn’t hitting the rock. It was passing through a thin, silent film of water—a vertical sheet, perfectly still, like a mirror made of nothing—and bouncing off something solid exactly 17.42 meters behind it. Something the eye couldn’t see.

He took one final shot: Coordinates recorded. Then the Leica’s battery died.