The narrative begins with Ishmael, a man seeking to escape the spleen by going to sea, who arrives in New Bedford and forms an unlikely friendship with Queequeg, a heavily tattooed harpooneer from a remote island. Together, they travel to Nantucket and sign on aboard the Pequod, an old whaling ship adorned with the bones of past kills. The ship is owned by the pious Bildad and the pragmatic Peleg, but it is commanded by the enigmatic Captain Ahab, a man who has lost his leg to a monstrous white sperm whale known as Moby Dick. Ahab remains hidden in his cabin during the initial days of the voyage, nursing a dark and consuming monomania.
As the Pequod sails southward into warmer waters, Ahab finally appears on the quarter-deck, standing on his ivory bone-leg and radiating a terrifying, regal authority. He reveals the true purpose of the journey to his crew, offering a gold doubloon to the man who first sights the white whale, and binding the sailors to his vengeance with a pagan oath. The voyage becomes a relentless hunt across the globe, punctuated by encounters with other vessels that bear grim warnings of Moby Dick's destructive power. The mates—Starbuck, the cautious and conscientious chief mate; Stubb, the carefree and pipe-smoking second mate; and Flask, the pugnacious third mate—each manage their boats with distinct philosophies of courage. Amidst the bloody labor of processing captured whales, the tension on board steadily mounts as Ahab's obsession deepens, driving the ship closer to a fateful confrontation with the leviathan.