The correct answer is the first one: Melville is building a mood of suspense.
Long before Ahab appears in the story, there is an atmosphere of mystery about the captain of the ship. The owners call in the crew in while Ahab is absent. Ishmael is told that Ahab is a man of few words but deep meaning; from the first moment, it is clear that the captain has a complicated personality. He is an "ungodly, god-like" man who has attended colleges as well as he has been among cannibals. Ahab is ungodly because he refuses to submit to a higher power. He does not worship or even acknowledge that there are forces beyond himself. Ahab is god-like in the sense that he represents a higher power; perhaps he even wants to be considered as a God.
The mystery is deepened as Ahab remains in his cabin through the first days of the trip. Ishmael grows anxious, checking the area outside the captain's cabin whenever the narrator goes on watch. When Ahab finally appears, in this chapter 28, he is an imposing figure whose haunted look sends shivers Ishmael's spine.
