Have you ever met someone who mistakes their beliefs for truths? Someone who doesn't understand that just saying something doesn't make it true?
But, what if? What if such a person's beliefs and words, however improbable, are actually an accurate perception and account of an 'objective' reality?
The challenge for any reader of The Turn of the Screw is to work out whether the main narrator's tale is one of delusion or verisimilitude.
For one reason or another, a group of friends meet to hear a ghastly-but-true tale read to them by Douglas, one of their number. The author of the tale, a now deceased friend of Douglas, claims the events described happened to her. Twenty year earlier she had obtained work as the governess of two young orphan children, Miles and Flora. Their uncle, who has custody of them, hands care for the children over to the governess and then promptly steps out of the picture. Then the ghosts turn up.
So now we have the bones of a gothic horror story: a big rambling house on a large, remote country estate, inhabited only by a handful of characters - the governess, the children and the housekeeper Mrs Grose. Oh, and the ghosts. And there are dark secrets aplenty.
What is then left to discern is whether the events described can be attributed to a supernatural cause or to a more mundane one. Henry James has been quite skillful in the weaving of this tale. There are enough clues and enough loose threads to keep the reader guessing right up until the end.