04 - Omnilingual by H. Beam Piper

Join an extraordinary expedition to Mars as a team of explorers uncovers the remnants of a once-advanced civilization that vanished thousands of years ago. Among the ruins, they find ancient books and documents filled with mysteries. Will they be able to discover the elusive Rosetta Stone that unlocks the Martian language and reveals the secrets of this long-lost race? (Summary by Mark Nelson)