Wings of Night

There are many great haunted house novels.there is only one about a haunted theatre. North Wales in the long hot summer of 1976: the Grand Theatre, Llandrudion Bay is a haunted building. Its owner and manager, the monstrous Mr James Wetherby Pierson, rarely visits the Grand but exerts power from afar, which is why some of his employees refer to him as "God." There is a mystery about how Pierson acquired the theatre from its previous owner, who is long dead but still seems to inhabit the place with a strange, stunted companion.
Then there is the town of Llandrudion Bay itself with its murky secrets, most of which are somehow connected with the theatre. Two young actors, John and Julie, join the company for a summer season of plays and find themselves playing out their roles in a place where the Living and the Dead, Heaven and Hell, Good and Evil, are in the dark wings, waiting to make an entrance on stage. Julie is a sensitive and recognises the evil spirits of the theatre before John does, but John trusts her and is ready to help her rescue Benny, one of the members of the company, from the very mouth of hell itself, which seems to lie beneath the stage of the Grand.
He also has to encounter alone the creature that comes out of this hell mouth - the horrible "Mr Chink."