A man, under morphine, experiences a vivid dream in which a winged spirit identifies itself as the Spirit of Morphine and carries his disembodied consciousness on aerial voyages across seas and polar skies. He observes cities by night, the aurora, a polar aperture revealing subterranean fire, maelstroms and northern lands, and then visits royal courts and glittering social scenes where political and philosophical ideas are discussed. The narrative alternates travel impressions, exotic landscapes, encounters with varied peoples and rulers, and reflective commentary on life, government, and the mysterious powers of sleep and drug-induced vision.