In October 2018, 39 journalists from 19 media in 12 countries published the CumEx Files and unveiled the biggest tax robbery in European history. Bankers, brokers and rich investors robbed over the years 55 billion euros from the treasuries of EU countries. Oliver Schröm, editor-in-chief of the German newsroom CORRECTIV, was one of the initiators and head of European research cooperation. He describes how this team of investigative journalists researched, how they evaluated 180,000 documents, how they got an insider to make a confession in front of their TV camera. Schröm shows how he and his colleague Christian Saleweski slipped into the role of billionaires and proved with the help of an offshore company in a spectacular undercover mission that these cheaters are plundering public treasuries not just in Europe but around the world.