The Turn of the Screw is written in an incredibly dense, winding, and circuitous literary style. For contemporary readers, the prose might feel frustratingly impenetrable at times, as James often uses double negatives and writes complex sentences with many dependent clauses that make it hard to track his use of nouns and pronouns—that is, it can be hard to follow what's happening!
For example, take this progression of sentences from the final scene, in which the governess is trying to get Miles to tell her why he was expelled from school. As she's questioning him, she turns and sees the ghost of Peter Quint staring through the window:
I felt a sick swim at the drop of my victory and all the return of my battle, so that the wildness of my veritable leap only served as a great betrayal. I saw him, from the midst of my act, meet it with a divination, and on the perception that even now he only guessed, and that the window was still to his own eyes free, I let the impulse flame up to convert the climax of his dismay into the very proof of his liberation.