The best way to acquire the reader's complete attention is by making the narrative simple, active, and prone to making connections. Henry James achieves this in The Turn of the Screw in several ways.
The use of a first person narrative
James uses a first person narrative in both the prologue and the governess's own narrative. This creates an instant bond between the reader and the story, since the reader may vicariously experience the feelings and emotions of the narrator. Also, since the narrator speaks from his or her own point of view, the reader can get insight on details that are only known to the narrator.
Conversely, since only the narrator's perspective what pertains to the story, the reader can only make assumptions and create his own conclusions as to what are the facts and ideas of other characters. In The Turn of the Screw the character of the governess is what leads the action, making us wonder whether she is telling a true story, or whether she is, indeed, mentally unstable. Hence, with only her testimony as our sole piece of information, the story becomes three-dimensional, reaching our conscious and subconscious levels while we create text-to-self connections.
The Gothic genre is known for building the atmosphere, and setting the tone and mood of a story from the start, and in a very defined way. In The Turn of the Screw, Henry James starts off novel in this typical Gothic tradition, by preparing the reader, in the prologue, to what will be a very scary tale.
THE STORY HAD held us, round the fire, sufficiently breathless, but except the obvious remark that it was gruesome, as on Christmas Eve in an old house a strange tale should essentially be, I remember no comment uttered till somebody happened to note it as the only case he had met in which such a visitation had fallen on a child.
Along with the format, the language and the application of everyday traits to each of the servants in the household, as well as to the children, make the story easy to get involved with.
The way in which James disturbs the reader is with the treatment of the topic that he chooses. We know that Miss Jessel and Peter Quint "corrupt" Miles and Flora during their lifetimes, and now after their deaths. While we as readers are not told directly which type of corruption the children have undergone, we still know that it is bad enough to grant an evil presence in the household. That suspense creates an enigmatic curiosity in the reader that can only be resolved by actively reading every detail. This is what contributes to the success and historical value of a novel.