I am going to take the case largely bceause it has interested me,

changed to: I am going to take the case largely [because] it has interested me,

Chapter IV

Duvall examined this house next door with a great deal of interest

changed to: Duvall examined this house next door with a great deal of [interest.]

"Nothing, so far. I confess the thing is somewhat of a puzzle.

changed to: "Nothing, so far. I confess the thing is somewhat of a [puzzle."]

Chapter V

...eyes of the two men were tent curiously upon her,

changed to: ...eyes of the two men were [bent] curiously upon her,