The Indus Valley civilization was one of the most advanced in the world for over 500 years. More than 1000 settlements sprawled across 250,000 square miles of what is now Pakistan and northwest India from 2600 BCE to 1900 BCE. It had several large, well-planned cities like Mohenjo-daro, common iconography, and a script no one has been able to understand. Linguists studying the Indus script don't know anything about the underlying language and there's no multilingual Rosetta Stone, but scholars have analyzed its structure for clues and compared it to other scripts. Most Indologists think it's “logo-syllabic” script like Sumerian...