Beneath the ocean floor, where volcanic vents push water past the point of boiling, a single-celled archaeon quietly performs one of chemistry's most demanding feats — breaking the near-unbreakable triple bond of nitrogen. Researchers in Bremen and Grenoble have now mapped the molecular machinery behind this ancient trick, finding in Methanocaldococcus infernus an enzyme that appears to predate all modern nitrogenases and operates where most life would simply cease. The discovery does not merely illuminate a corner of deep-sea biology; it opens a window onto a universal principle underlying ni