Edward Bulwer-Lytton 
The Coming Race 

The Coming Race is a science fiction novel by Edward Bulwer-Lytton. The novel centers on a young, independently wealthy traveler who accidentally finds his way into a subterranean world occupied by beings who seem to resemble angels and call themselves Vril-ya. The hero soon discovers that the Vril-ya are descendants of an antediluvian civilization who live in networks of subterranean caverns linked by tunnels. It is a technologically supported Utopia, chief among their tools being the ‘all-permeating fluid’ called ‘Vril’, a latent source of energy which his spiritually elevated hosts are able to master through training of their will, to a degree which depends upon their hereditary constitution, giving them access to an extraordinary force that can be controlled at will. The powers of the will include the ability to heal, change, and destroy beings and things. The Vril-ya will run out of habitable spaces underground and start claiming the surface of the Earth, destroying mankind in the process if necessary.