A Gothic setting is often old, decaying, haunted, or a secret. Jekyll's laboratory is a separate wing or building from his main home, and it is accessed through a courtyard. Stevenson foreshadows the final scene of the story when Utterson and Enfield, on their "usual walk," take the "back way to Dr. Jekyll's." There, standing in the "premature twilight" of the courtyard, they see Dr. Jekyll in an upper window. After a short, depressing conversation with him, they see his face change to an "expression of ... abject terror," and he slams the window down.
One characteristic of it being gothic themed is that it is dark and uncomfortable. the story shows the lack of control of man and the imploration of mercy. Its mysterious and strange.
The sentence that has illogical comparison is the second example - A parrot's feathers are more colorful than a parakeet. It should be ... than a parakeet's.
