Answer:
Lovecraft's purpose in revealing that the narrator was in a crypt or tomb rather than a castle created an interest in its readers to know what will happen after the narrator will go into the human world.
Step-by-step explanation:
"The Outsider" is a short story written by H. P. Lovecraft. The story is about an unnamed narrator, who finds himself in a "castle." After having no human contact for long, the narrator decides to come out of his castle into the human world.
But Lovecraft reveals halfway through the story that the narrator is not in a castle but a tomb or crypt. This revelation in the midway affects the readers and makes them more interested to know what will happen when the narrator will try to make human contact. This brings a turning point in the story. Therefore, the purpose of this revelation by Lovecraft was to keep his readers engaged and interested.