Some of the mystery of the voyage is still unexplained. What were those shapes that Ishmael thought he saw entering the boat on Christmas morning? Are they related to the strange sounds heard below the hatches near the captain's quarters? Ahab may know, but he is not talking. The captain spends most evenings trying to guess where Moby Dick might be. Ishmael assures us that whales do migrate in certain patterns, but the sperm whale's routes vary more than most, and it's a big world.
In Chapter 45, Ishmael attempts to convince the reader that the story he tells is consistent with possibility. As if he were swearing an oath, Ishmael reveals that Ahab is justified in believing that his own harpoons still ride Moby Dick and that he may well be the one to kill the White Whale; such odd things have happened. Nor is it unique that Moby Dick is recognizable; so are several other sperm whales, some given names. Foreshadowing events later in the novel, Ishmael warns that hunting whales in an open boat is very dangerous and that sperm whales have even been known to attack and sink large ships. Ishmael is concerned that, without these "plain facts, historical and otherwise," the reader "might scout at Moby Dick as a monstrous fable" or, worse, an allegory. He asks us to suspend our disbelief, we must suspect, because this is a grand, mythic journey with so many tempting, hidden meanings. Ishmael asks us to stick to the story.
