It was Friday afternoon, and Maria arrived in Madrid for a weekend trip. She felt excited to see the city. At the airport, she followed the signs for the metro, bought a ticket from the machine, and checked the map on her phone. She put the ticket in her pocket, reached for her wallet—and stopped. It was not there. She searched her backpack, her coat, and her jeans. Nothing. A wave of panic rose in her chest. Her wallet had her ID card, her bank card, and fifty euros in cash. She took a slow breath and went to the information desk. “Excuse me,” she said. “I think I lost my wallet.” The woman behind the desk nodded calmly. “Where did you last see it?” “In the shop, maybe… or at the ticket machine,” Maria said. “First, block your bank…