Why will you say that I am mad?
The story is a defence that convicts itself. Every claim of calm is evidence against him.
A narrator whose account cannot be trusted — through ignorance, self-interest, madness or a deliberate lie. The reader has to assemble the real story from the gaps the narrator leaves.
Check what the narrator insists on. Insistence is usually a wound. Then check what they skip, and whether other characters contradict them.
Because self-justification is how people actually speak, and because a reader who must judge becomes implicated.
Why will you say that I am mad?
The story is a defence that convicts itself. Every claim of calm is evidence against him.
The governess alone sees the figures.
Either the ghosts are real and the children are in danger, or the narrator is dangerous. James leaves the verdict to you.
The beautiful prose of a man describing his own crime.
The style is the alibi. The reader's task is to keep noticing what the sentences are designed to make you forget.
An unreliable narrator is not automatically lying. The point is that the reader must judge, using evidence the narrator did not intend to give.