Nevada is located atop seismic fault zones where fissures in the earth bring the brimstone close to the desert’s mantle. Ten thousand feet below the ground, flowing water comes in contact with superheated rock, bringing to the surface fumaroles (steam vents), geysers, boiling mud pots, and (more commonly here) hot springs. When I approach one of these thermal features, a surreal oasis interrupting the ordinary landscape, I feel connected to the inner warmth of life’s cradle, a visitor to the world of geological time.