What is the theme of the short story The Open Window by S?aki

There are many possible themes to "The Open Window".  Like
all literature, theme depends on how a reader interprets the text.  One possible theme
of the short story is distrust.  Framton Nuttel is visiting the home of Mrs. Sappleton. 
Nuttel is visiting the home because he has a nervous disorder and needs to seek out a
place that is calm and quiet- the exact treatment of his disorder is not noted, but a
reader could assume that his doctor is simply prescribing rest.  Once at the home,
Nuttel meets Vera, the niece of Mrs. Sappleton. Nuttel tells Vera of his reasoning for
the visit.  The young girl then turns the tale of this being the exact day of her
uncle's disappearance.  Here is where the theme is enacted.  Vera knows of Nuttel's
nervous disorder, his desire to rest at her aunt's home to recuperate, and, instead of
helping with Nuttel's recovery, she compounds his ailment by creating a ghost story to
which, to Nuttel's surprise, becomes real. Nuttel needed to trust in those of whom he
sought out help; instead, those he sought out failed to help him at all.  Therefore, the
theme of the text is mistrust- the only words that Vera mentions that are true are those
of the names of her family members.