Jules Verne 
The Underground City: The Black Indies 

Miner James Starr, after receiving a letter from an old friend, leaves for the Aberfoyle mine which was supposed to be mined out a decade earlier. Much to James’ surprise he finds Simon Ford and his family living deep inside the mine. Simon found a large vein of coal in the mine but they have to deal with mysterious and unexplainable happenings in and around the mine.