In the 18th century, Governor Weatherby Swann (Jonathan Pryce) and his daughter, Elizabeth (Keira Knightley), set sail on the HMS Dauntless. During their voyage, Lieutenant Norrington's ([Jack Davenport]) crew discovers a shipwrecked survivor named Will Turner (Orlando Bloom). Curious, Elizabeth takes a gold medallion from Will's neck, just before glimpsing a ship with ominous black sails.
Fast forward eight years, and in Port Royal, Jamaica, Norrington has been promoted to commodore and proposes to Elizabeth at Fort Charles. The sheer constriction of her corset causes her to faint and tumble into the water, stirring the medallion on her neck into action. At this point, the Royal Navy possesses two ships: the Dauntless and the Interceptor. The latter is renowned for its speed, second only to the cursed Black Pearl, helmed by a legendary captain whose malice is said to have driven him from the fiery depths of hell.
Amidst this chaos, Captain Jack Sparrow (Johnny Depp) arrives, drawn by the prospect of commandeering a ship. When he spots Elizabeth in distress, he leaps into the water, saving her and noticing the gold medallion hanging from her neck. However, he soon finds himself evading capture by Commodore Norrington, who recognizes Jack's infamous pirate brand.
Meanwhile, Will, now a blacksmith, crosses paths with Jack in his workshop when Jack attempts to rid himself of his chains. A fight ensues, and ultimately, Jack is apprehended. Elizabeth and Will share a bond of friendship that complicates when the dreaded Black Pearl launches an attack on Port Royal, seeking the very medallion that Elizabeth possesses. The chaos escalates as the pirates, led by Pintel (Lee Arenberg) and Ragetti (Mackenzie Crook), storm the town in a search for the treasure.
During this tumultuous event, Elizabeth invokes parley, granting her a temporary reprieve as she meets Captain Barbossa (Geoffrey Rush). She cleverly pretends to be "Elizabeth Turner" to disguise her identity, striking a deal with Barbossa to spare the town in exchange for the medallion. Barbossa discloses that the medallion is one piece of a cursed Aztec treasure, beset by a dark fate that ensures eternal damnation for those who dare to spend even a fraction of it.
The crew, cursed and undead under the light of the moon, can reclaim their humanity only by returning all the gold along with their blood. Barbossa, under the misconception that Elizabeth is Bootstrap Bill Turner’s child, schemed to use her blood to break the curse. Meanwhile, Will, determined to rescue Elizabeth, seeks the assistance of the elusive Jack, but Norrington rebuffs the idea of collaborating with pirates.
To save her, Will frees Jack, and they set out to locate Elizabeth on the Black Pearl. As they concoct a distraction for Norrington to commandeer the HMS Interceptor, Will grapples with the revelation that his father was indeed a pirate. The adventure leads them to Tortuga, where they rally a crew, including Joshamee Gibbs ([Kevin R. McNally]), eager to aid Will upon realizing who he really is.
Arriving at Isla De Muerta, Will and Jack manage to sneak into the treasure grotto, but their efforts to lift the curse with Elizabeth’s blood fail. Barbossa, enraged at the delays that have spanned a decade, demands to discover the true heir of Bill Turner. In the midst of this mayhem, Elizabeth and Will manage to escape with the medallion aboard the Interceptor, whereas Jack is captured and confined to the brig of the Pearl after revealing that he knows the true identity of the real Turner child.
A fierce battle unfolds between the Black Pearl and the Interceptor, leading to the capture of the crew and delivering a significant blow to the ship. Will, putting his own safety on the line, turns himself in to ensure Elizabeth's freedom, while Jack and Elizabeth find themselves marooned on the very island that had once been Jack’s prison. The next day, after an ingenious smoke signal, they are rescued by the Dauntless.
Elizabeth, now swayed by compassion, accepts Norrington's marriage proposal but insists on rescuing Will first. As the night deepens, Jack and Norrington plot an ambush against the pirates, while Jack secretly prepares to snatch a gold coin to seize immortality before engaging in a duel with Barbossa in the cave.
As gunfire erupts between Norrington's men and the skeleton crew aboard the Dauntless, Elizabeth stealthily sets Jack's crew free on the Pearl after engaging in combat herself. Their orchestration leads to a climactic moment when Sparrow shoots Barbossa just as Will restores both remaining coins into the chest, which lifts the curse. Now mortal, Barbossa succumbs to Jack's bullet, while the rest of the cursed pirates face their judgment.
Returning to Port Royal, Will professes his love to Elizabeth before rescuing Jack from the gallows. In a show of loyalty, Elizabeth sides with the two, favoring Will over Norrington, leading to a stand-off where Norrington relents. In a dramatic final twist, Sparrow plunges into the sea but is quickly rescued by the Black Pearl and its crew. Governor Swann ultimately grants his blessing for Will and Elizabeth's union, while Jack Sparrow assumes command of the Black Pearl, sailing toward the horizon unfettered by the constraints of his past.
