The word arrived in Dr. Elara Venn’s inbox at 3:17 a.m., attached to a single audio file. The subject line was blank. The sender was her estranged father, a man she’d assumed was long dead.

Elara descended alone. The air grew thick, smelling of ozone and wet chalk. At the bottom, carved into a natural amphitheater of basalt, were symbols no human civilization had made. Not letters. Not pictograms. They were sound fossils —grooves shaped exactly like the vocal tract movements needed to produce specific phonemes. Run your finger along one, and your throat would try to mimic the forgotten noise.

Gurapara! they had cried, the first time they saw fire rain from the sky.