Why does Miss Strangeworth mail her letters at the post office after it has closed?

Miss Strangeworth appears on the surface to be a harmless little old lady. In reality, however, she is a thoroughly unpleasant character, who, among other things, acts and feels like she owns the town. After all, her grandfather built the first house on Pleasant Street, a fact she often shares with tourists passing through town who stop and admire her roses. She is also an interfering old busybody, dispensing homely advice to all on her...

Miss Strangeworth appears on the surface to be a harmless little old lady. In reality, however, she is a thoroughly unpleasant character, who, among other things, acts and feels like she owns the town. After all, her grandfather built the first house on Pleasant Street, a fact she often shares with tourists passing through town who stop and admire her roses. She is also an interfering old busybody, dispensing homely advice to all on her daily rounds.

After Miss Strangeworth returns home she retreats to the genteel tranquility of her pretty sitting room. Here, at her writing desk, she composes a series of vicious poison-pen letters addressed to various townsfolk. She always mails them at the new post office, "shiny with red brick and silver letters." Additionally, she always makes sure to time her visits to coincide with the onset of darkness. By doing this, she is much less likely to be exposed as the writer of all those horrid little letters. However, the best-laid plans do not always go according to plan, as Miss Strangeworth is soon to discover.