Wagner’s abundant evocation of fogs and fires in Der Ring des Nibelungen was unprecedented. The water vapor used in 1876 at Bayreuth’s inaugural festival provided Wagner with his most “real” stage ingredient. Additionally, the chapter proposes, steam could mediate between bodies and painted scenery and could both enliven and veil open transformations. Yet while onstage vapors became a visual icon of the Ring, steam also drew attention to tensions within Wagner’s works and theories. Although intended to evoke unspoiled mythic nature, this novel and multisensorial technology generated smells and sounds associated precisely with the industrial modernity that Wagner’s Gesamtkunstwerk was to overcome. Allegorically, steam’s rendering of both fogs and fires anticipated the vanquishing of nature in the Ring by fire, the oldest human technology. Ultimately, its multivalence allowed steam to transcend both scenic realism and the operatic stage to become a cyp her of both modernity and performativityper se.