Since 2016, Colombian cyclists have topped the podiums in the French, Spanish and Italian tours. Yet these successes hide a dark secret: a doping problem. Along with Costa Rica and Italy, Colombia has the highest number of cyclists sanctioned for taking performance-enhancing drugs. The Colombian anti-doping agency is trying to track down and test potential cheaters, with some 30 doctors spread across the country. But their mission is far from easy, as our team in Colombia reports.