Set during the time of the Mexican War, Jack Tier is a much more realistic sea story than the nautical romances Cooper wrote in the 1820s and 1830s. It begins in New York City where the Molly Swash, tied up at an unattractive wharf near beer halls and an almshouse, is in the process of departure for Key West. Although a sleek, clipper-built brig, the Molly Swash, like her captain, Stephen Spike (now fifty-six), shows signs of age. Most of the crewmen too are beyond the prime of life, and the Negro steward and cabin "boy," Josh, is sixty. The only young man among the ship's company is Henry (Harry) Mulford, the first (and only) mate. Three passengers are aboard the brig: Rose Budd, an intelligent and beautiful girl not yet nineteen; Mrs. Budd, her aunt, in late middle age but already failing mentally; and the latter's Irish maidservant, Bridget (Biddy) Noon. It is Mrs. Budd's opinion that Rose has incipient tuberculosis and that a sea voyage will cure her malady. She does not tell this to her niece, however, but pretends that she herself has pulmonary problems that a cruise may relieve. Mulford is certain that neither woman has any lung disease. He soon does discover, though, that the widow has a less serious failing, a confirmed case of nautical malapropism. Her late husband, a sea captain, had, with a perverted sense of humor, carefully mistaught her shipboard terms and seaman's lingo in order to amuse himself and his cronies at her expense. As they cast off, Captain Spike exhibits a degree of anxiety that suggests he has something to hide. He is disturbed by the appearance nearby of a customs vessel. When the brig is only a few feet from the dock, he is hailed by a tall man who wants the job of harbor pilot to carry the brig through Hell-Gate, a narrow channel in the East River. He is also hailed by a short, fat, waddling little figure with a cracked, dwarflike voice, a seaman who, claiming to be a shipmate of twenty years earlier, asks Spike for a berth aboard his ship. Spike rejects both bids for employment and directs the Molly Swash toward Hell-Gate, which he intends to navigate with his own skill. When the would-be employees follow, however, in a smaller but faster boat, Spike grows so upset that he permits his vessel to graze a dangerous rock in the passage.