A recent study by scientists from Monash University revealed the presence of hydrogen-producing enzymes in archaea, a discovery that challenges previous assumptions and offers new insights into the potential of hydrogen as an energy source. The enzymes, known as hydrogenases, were thought to exist only in bacteria and eukarya but were found to be present in archaea as well. This finding suggests that archaea have been utilizing hydrogen for billions of years, potentially influencing the evolution of eukaryotes through processes like endosymbiosis. By identifying [FeFe]-hydrogenase enzymes in archaea, which are smaller and more complex than those in other domains, researchers are paving the way for more efficient hydrogen energy systems. This discovery has significant implications for industries currently using chemical catalysts for hydrogen usage, as biological catalysts found in archaea could offer a more sustainable and effective alternative. The study not only uncovers ancient biological processes but also presents a pathway towards a zero-emission future by utilizing the unique capabilities of archaeal enzymes. Understanding how archaea have evolved to consume and produce hydrogen could revolutionize energy systems and contribute to a more sustainable future for humanity.