In 1805, in the Atlantic Ocean just off the coast of Brazil, the HMS Surprise, a British frigate commanded by Captain Jack Aubrey, comes under an unexpected attack by a French privateer, the Acheron. When return fire from the Surprise proves ineffectual and coxswain Barret Bonden reports their ship’s rudder has been shot away, Jack orders boats lowered to tow his damaged vessel into a fog whiteout. Later, Jack speculates about the Acheron ’s stealth, speed and apparent impregnability and wonders how the French ship, which the Surprise had been trying to locate for seven weeks, found them. Jack then oversees the ship’s numerous repairs while his close friend, Irish surgeon Stephen Maturin, tends to the many wounded. Determined to fulfill his orders to capture the French privateer, Jack refuses to consider returning to England for refitting and orders repairs to be made while the ship rests on the coast’s nearby shoals. Learning that Stephen has had to amputate young midshipman Lord Blakeney’s right arm, Jack brings Blakeney a book about the exploits of famed British naval hero Horatio Nelson, who also suffered the loss of a limb in battle. The crew watches with interest when Stephen performs surgery on the ship’s oldest crew member, Joe Plaice, who has sustained a serious head wound. That evening in the great cabin, Stephen joins Jack for their regular meeting to play violin and cello duets. A few days later as the Surprise returns to open sea, carpenter’s mate Joseph Nagle, captain of the mizzen top William Warley, and another sailor bring Jack a replica of the Acheron , which the crew has nicknamed the “phantom ship.” Nagle explains that Warley had witnessed the boat under construction in a Boston shipyard and built the model with exact detail. Jack is fascinated by the double hull design that allows the ship to sit high in the water and move at great speed. Meanwhile, up on deck, the crew celebrates when Plaice utters his first words since his injury. When older midshipman Hollom joins the crew’s lusty singing, however, the men are inexplicably offended. The following day, Jack is stunned when the Acheron abruptly appears on the horizon closing in behind them, and orders the Surprise to make a top speed escape. Jack then orders a decoy raft made and that night has it placed in the water with lit lanterns and cut adrift to attract the Acheron fire while the Surprise slips away. The following morning the officers are impressed to find that Jack has maneuvered the Surprise in a vast circle and come up behind the Acheron . Jack presses his advantage, chasing the Acheron as it hastily retreats southward toward Cape Horn. Near the cape, a fierce storm abruptly closes in and the French ship disappears. Jack orders the Surprise ’s sails taken in, and as Hollom climbs to the mizzen top to assist Warley, the mast snaps, flinging Warley into the sea. As the mast rigging pulls the Surprise sharply over on its keel, Jack and Nagle are forced to cut the ropes to save the ship, but cannot rescue Warley. In private, Stephen comforts Jack but questions whether Jack’s pursuit of the Acheron has become a reckless obsession. Jack admits his orders were to follow the French only as far as Brazil, but is confident he can catch and defeat the privateer despite its superiority. The Surprise continues southward and the temperature drops drastically, bringing snow and ice. Days later, the crew celebrates when the ship turns northward and Jack confides in his officers that he believes the Acheron is headed to the whaling waters around the Galápagos Islands. Stephen, an amateur botanist, is delighted at the prospect of exploring the life on the “enchanted islands” and interests Blakeney in various studies of insect and plant life. Upon arriving at the islands, the Surprise rescues a small boat filled with the survivors of a whaling vessel destroyed by the Acheron . Confirming the French ship’s direction, Jack orders immediate pursuit. When Stephen angrily protests that Jack assured his island exploration, Jack reminds him the Surprise is a navy battle ship. In anticipation of catching his elusive foe, Jack drills the gunnery crews repeatedly, only to sail into the “doldrums,” a hot, airless tropical region that leaves the ship immobile. Led by the now-fully-recovered Plaice, the crew comes to believe that the Surprise is carrying a “Jonah,” or a curse in the guise of Hollom, who is present wherever misfortune occurs. The feeling is heightened when Jack is forced to flog Nagle for flagrantly displaying disrespect for Hollom in front of the crew. Jack advises Hollom, a misfit who has twice failed the officer’s exam, to earn the men’s respect, but the midshipman remains anxious and fearful. Stephen scoffs at the men’s superstitious talk of a curse and is dismayed when Jack supports his crew. On night watch a few days after the flogging, Hollom thanks Blakeney for his kindness and then throws himself overboard. Just after Hollom’s funeral service, the wind picks up and Jack again sends the Surprise in search of the Acheron . As the ship nears the islands, Stephen enthusiastically tracks an albatross flying close to the railing and is accidentally shot by Marine Capt. Howard as he fires at the bird. Alarmed by his friend’s grave injury, Jack weighs anchor at the islands, where an operating tent is set up for surgeon’s assistant Higgins. Stephen refuses to allow Higgins to operate, however, and conducts the surgery himself as Jack’s steward, Preserved Killick, holds a mirror for him to see his wound. Stephen recovers over the next several days and confesses his guilt to Jack over preventing the Surprise from continuing her mission. When able to walk, Stephen takes Blakeney and Padeen along the volcanic surface of the island to retrieve various animal, insect and plant specimens. Excited by the possibility of capturing a flightless bird, Stephen climbs a hill where he discovers the Acheron anchored in a cove on the far side of the island. Abandoning their collection, Stephen and the others hasten to report to Jack. Inspired by a phasmid, an insect that disguises itself to confuse predators, Jack orders the ship to be disguised as a whaling ship, hoping to lure the Acheron to them. The plan succeeds and the Surprise makes a stunning attack on the larger French ship. Jack leads a boarding party onto the enemy vessel, leaving Blakeney in charge of the British ship. On board the Acheron , a desperate hand-to-hand battle ensues while Blakeney’s quick action prevents the French ship’s cannons from firing. After overcoming the enemy crew, Jack, who has been slightly wounded, searches for the French captain. On the lower deck he finds a physician hovering over the dead captain, and the doctor presents the captain’s sword in surrender. Despite the victory, Jack suffers the loss of many crewmen, including Ship’s Master Mr. Allen and young Peter. At services for the dead, Jack posthumously promotes Peter to lieutenant so that his family may receive a pension. Jack then promotes Lt. Thomas Pullings to captain and awards him command of the Acheron , which sets sail for Jamaica. Before heading for England, Jack sets course for the Galápagos, having promised Stephen that he might return to his exploration. When Stephen comments on the lack of medical care on the Acheron , Jack reveals their physician surrendered the ship to him. Stephen relates that members of the French crew informed him that their doctor had died weeks earlier. Realizing he has been tricked once again, Jack orders a “beat-to-quarters” and the Surprise comes about to pursue the Acheron.