Ask anyone what San Antonio is, and the honest answer is the River Walk and its position on the border -- both real, both enormous. Underneath that visible identity runs a second economy nobody sees: a military information-warfare unit that trained the people, a private company almost nobody's heard of that turned what they learned into the backbone of Cisco's global security business, and a university that quietly became one of the most credentialed cybersecurity research institutions in the country before any of it had an official name.