For the current season of "Team Wallraff - Reporters undercover", RTL reporters infiltrated three different industries over a period of more than eight months. Their mentor: Günter Wallraff, Germany's best-known investigative journalist, who for decades has repeatedly exposed serious abuses in the world of work with his undercover reports - without shying away from powerful institutions, big brands or names. The 71-year-old is not only on hand to advise his team. In every episode he slips into at least one important role.