Contour Lines.
A perceived line that marks the edge of a figure as it curves back into space. Contour lines are created by the edges of things. Contour lines are lines that surround and define the edges of a subject, giving it shape and volume
It seems that you have missed the necessary details for us to answer this question so I had to look for it. Anyway, here is the answer. Readers must revise their predictions about Rainsford after reading the second excerpt because initially it would seem that he plunges to his death, but he actually <span>has lured and trapped his guests. Hope this helps.</span>