How tension is built up and sustained in the red room, the speckled band and the ostler

The Red Room
We as the reader are immediately attracted to the title "The Red Room" because it raises so much curiosity and leaves many unanswered questions. "What is the red room?" "Why is it red?" The colour red is associated with fear, danger and maybe even blood so is the room dangerous? Our minds can create so many thoughts about this one title that we are filled with an urge to read on to find the answers to our questions.
In a short story, we are influenced by the writers first and last lines, so they have to carry meaning.
"I can assure you,' said I, 'that it will take a very tang…