More and more bacteria are becoming insensitive to antibiotics, not least due to excessive drug consumption. According to the EU, this problem could soon become as explosive as the environmental issue - and antibiotic resistance threatens to become one of the main causes of death worldwide. Research must therefore find alternatives - not miracle cures, but permanently effective drugs. There has already been one in the past: One hundred years ago, the French biologist Félix d'Hérelle discovered mysterious "bacteria-eating" viruses, known as bacteriophages or phages for short. He used these to successfully treat bacterial infections before the development of antibiotics, but his method was forgotten again. Is bacteriophage therapy the miracle medicine of the future?