In the picturesque West Coast of England during the year 1765, a young lad named Jim Hawkins resides with his mother at a humble country inn that they manage together. Their tranquil life takes a dramatic turn when Captain William Bones, a frail and enigmatic lodger with a background in merchant marine, hands Jim a treasure map after a chilling confrontation with two nefarious pirates. The second pirate, distinguishable by a pronounced scar on his face, delivers a foreboding message marked with the infamous black spot. On that fateful night, the inn is shaken by the death of Captain Bones, leading Jim to unveil the treasure map to Squire Trelawney. The astute Trelawney immediately recognizes the map as belonging to the infamous buccaneer Captain Flint, which prompts him to finance an adventurous quest to uncover the legendary pirate's lost fortune.
Trelawney sets his plans into motion by hiring Captain Smollett and his formidable vessel, the Hispaniola. Accompanying them on this perilous journey are Dr. Livesey, serving as the ship's doctor, and young Jim as the intrepid cabin boy. However, before their voyage begins, Trelawney encounters Long John Silver, a cunning one-legged innkeeper who also serves as a cook. Silver's charm and obvious intelligence earn him the trust of Trelawney, who agrees to let him recruit a crew for their expedition. As unforeseen relationships build, Silver fosters a friendship with Jim that deepens the complexities of their journey.
Doubt and suspicion creep into Captain Smollett as he voices his concerns over the crew’s loyalty to Trelawney. He reveals that the true nature of their adventure appears to be common knowledge among the dissenters. As they venture forth across the sea, Jim inadvertently overhears a conspiratorial discussion between Silver and his crew regarding a planned mutiny. To his alarm, Jim uncovers that the unscrupulous figures recruited by Silver boast backgrounds as part of Captain Flint's infamous crew, with Silver having once served as their cook.
Upon reaching the storied Treasure Island, Silver cunningly proposes to tow the ship using two of its rowboats to a secure harbor. However, chaos erupts when Silver's man Merry leads a mutiny aboard the Hispaniola. Thanks to Jim's warning, Captain Smollett is prepared and able to fend off the insurgents, imprisoning them below decks. In a desperate bid for power and control, Silver cuts the rowboats adrift and makes off for the shore, taking Jim with him as a hostage. Undeterred, Smollett, Trelawney, and Livesey follow them onto the island, leaving a couple of loyal guards aboard the ship.
On the island, as fate would have it, Jim manages to break free and encounters Ben Gunn, a scruffy sailor who has been marooned on the island for five long years thanks to Flint's ruthless machinations. Ben shares with Jim the secret of his handmade boat and guides him to Flint's stockade, where they reunite with Smollett and their allies. Meanwhile, Merry escapes, commandeers the ship, and hoists the notorious Jolly Roger flag.
In a fierce attempt to reclaim his authority, Long John Silver returns to the Hispaniola, arming his men and strategizing to take the stockade back. Despite their numerical disadvantage, Silver seeks a parley with Smollett, but his overtures are met with steadfast rejection, triggering a fierce assault on the stockade. The ensuing battle results in heavy casualties among Silver's crew, and in the chaos, Silver himself inflicts a grievous wound on Smollett before retreating. Understanding that the tide could turn at any moment, Smollett realizes that Silver could maneuver the Hispaniola into a damaging position against their defenses.
Under the shroud of night, young Jim seizes the opportunity to steal Gunn's little vessel and embarks on an audacious mission to cut the Hispaniola's anchor. During this risky escapade, he witnesses a violent quarrel among Silver's men, resulting in one of them being murdered by another. As Jim's daring escapade continues, he finds himself pursued by the treacherous Israel Hands, resulting in an intense standoff in the ship's rigging. Jim's survival instinct kicks in, and despite being injured, he manages to take out Hands, seizes control of the Jolly Roger, and proudly raises the Union Jack in defiance.
Despite his wounds, Jim endures the long journey back to the stockade, only to discover that it has been taken over. In a shocking turn of events, Jim finds Long John Silver draped under Livesey's coat as Smollett's spot has been overrun. In a twist of fate, Silver discovers the treasure map within Jim's belongings, setting off a chain of events that thrusts them into discord. The mutiny continues to brew among Silver's men as they express a desire for revenge against Jim.
The climactic moments unfold as Jim and the crew, led by Silver, navigate the perilous terrain of the island in search of Captain Flint's treasure. Their excitement turns to dismay upon discovering that the treasure they sought—an astounding £700,000—is not where the map indicates. Facing the consequences of their disappointment, the remaining crew turns against Silver in a fit of rage, pushing the once-allied cook into a dangerous confrontation.
In a remarkable twist, Ben Gunn reveals that he had secretly unearthed Flint's treasure years prior, leading them to a hidden trove of riches concealed in a cave. Yet, amidst this newfound wealth, Captain Smollett remains steadfast in his pursuit of justice, demanding Silver's capture to face the courts in England. Resolved to strike a balance between justice and mercy, Jim Hawkins, alongside Squire Trelawney and several loyal sailors, transport Silver back to the Hispaniola aboard a rowboat laden with treasure.
As tensions soar, Silver seizes Jim's pistol and attempts to assert dominance, compelling Trelawney and the crew to abandon ship. With the power dynamics shifting rapidly, Jim finds himself tested as he must navigate the turbulent waters of loyalty and protection. Ultimately, Jim’s compassion surfaces as he assists Silver, pushing off into the depths of the ocean, where a bittersweet farewell unfolds—one marked by the complexities of their tumultuous journeys and the ties that have formed between the treacherous pirate and an innocent boy caught in a grand adventure.
