All at once, above them, they saw the sky again. The clouds, no longer red, had become a peculiar luminous blue-white, drifts and depths of them, as though illumined by moon rather than sunlight, between which roared still the deep fathomless cobalt of afternoon.
Birds were sailing up there, ascending higher and higher. Infernal birds of Prometheus!
They were vultures, that on earth so jealously contend with one another, defiling themselves with blood and filth, but who were yet capable of rising, like this, above the storms, to heights shared only by the condor, above the summit of the Andes–
Under the Volcano, Malcolm Lowry