For over two decades, explorers of the deep ocean have been enthralled by volcanically driven black smoker hydrothermal systems hosting organisms that live under some of the most extreme conditions on Earth (e.g., Corliss et al., 1979; Jannasch and Mottle, 1985; Grassle, 1986; Delaney et al., 1992; Humphris et al., 1995; Humphris and Tive, 2000; Van Dover, 2000; German et al., 2004; Wilcock et al., 2004). These systems are found on some of the youngest, hottest rocks on our planet located along the global mid-ocean ridge spreading network. Black smokers result from the seepage of seawater through cracks in the seafloor and its subsequent heating at depth by hot or molten basaltic rocks to temperatures >400°C (e.g., Von Damm et al., 2003). The superheated fluid, which is rich in dissolved metals and gases from chemical exchange with the hot rock, buoyantly rises to the surface. Until a few years ago, the billowing jets of metal sulfide- and gas-laden fluids were believed to typify submarine hot spring systems. However, in 2000, a serendipitous discovery of an entirely new venting system was made that was as profound and surprising as that of the first black smokers (Kelley et al., 2001). This new venting system, called Lost City, is unlike any environment ever visited. Investigation of this site is changing our views not only about the conditions under which life can thrive on our planet but, perhaps, on others as well.