In May 2019, the real estate agency California Outdoor Properties added a luxury property to its portfolio for $6.4 million. It was a luxury ranch located in Pescadero, a small town on the California coast with fewer than 1,000 inhabitants. The plot covered 75 acres of wooded land, three catfish ponds, a stream surrounded by willows, green fields stretching to the horizon, and a majestic European-style house crowned by a terraced tower. The property boasts four bedrooms with panoramic windows, six bathrooms, a library, and an office. It was the house where Dee Hock lived for over twenty years when she decided to live a quieter life. Perhaps this name doesn't mean anything to you, but it's the reason why you carry a credit or debit card with a specific logo in your wallet today: Visa. Who was he, and how did he create this global financial giant?