The exchange of nitrogen between the atmosphere and organic matter is crucial for life on Earth because nitrogen is a major component of essential molecules such as proteins and DNA. One major route for this exchange, discovered only in the 1990s, is the anammox pathway found in certain bacteria. It proceeds via hydrazine, a highly reactive substance used by humans as a rocket fuel. Researchers at the Max Planck Institute for Medical Research, in cooperation with scientists from the Max Planck Institute for Biophysics and Radboud University in the Netherlands, now describe the structure of the enzyme performing the last step in this process: turning hydrazine into nitrogen gas and harvesting the energy set free in this way. The results, which were just published in Science Advances, show an unprecedented network of heme groups for handling the large number of electrons released during the chemical conversion.