Leo nodded, pulling up a graph on the screen. It looked like a city skyline at midnight—a series of sharp peaks rising from a noisy baseline, each at a specific angle (2θ). “It’s beautiful,” he whispered. “But it’s a ghost. I’ve tried the old PDF-2 database. Nothing matches.”

“Let me tell you a story, Leo,” Elara said, pulling up a chair. “About how we learned to read the language of dust.”

“By eye,” Elara corrected. “You’d take your unknown sample’s pattern, pick your three strongest peaks, and flip through the ‘Hanawalt Search Manual’—a book of numbers—until you found a candidate. Then you’d check the rest of the peaks. It could take days. A PhD student’s entire thesis could be derailed by a single mismatched peak at 2θ = 28.4°.”

She tapped her keyboard, pulling up the PDF-4+ database. “Now, you don’t flip cards. An algorithm does it in 0.2 seconds. But the soul is the same: a library of the universe’s crystal lattices, built by the JCPDS.”

He closed the laptop. The diffractometer hummed, ready for the next mystery.

And the library of dust grew by one more peak.

She placed the card back in the drawer.

“What is that one?” he asked.