Henry Kuttner - The Well of the Worlds

"The Well of the Worlds" is a science fiction novel by American author Henry Kuttner (1915-1958), about Sawyer, who investigates ghosts in a mine, finds ancient beings from another world and when he finds a passage between the dimensions and is then tossed adrift into a world where islands are floating in the sky and where he discovers the secret of the mysterious Well of the Worlds.