In the heart of bustling New York City, Joan Wilder (played by Kathleen Turner), a cherished romance novelist known for her captivating tales of love and adventure, finds her life taking a dramatic turn. After completing her latest book, she meets her editor, Gloria, only to receive a mysterious letter from her neighbor, Mrs. Irwin. This letter contains an enigmatic map bequeathed by her recently deceased brother-in-law, Eduardo. Little does Joan anticipate that this innocuous gesture would trigger a whirlwind of perilous events that lead her around the globe.
As she steps out of her apartment, an intruder attempts to break in but is swiftly discovered and killed by the building superintendent. Returning home to find her apartment ransacked, Joan receives a frantic call from her sister, Elaine, Eduardo's widow, who reveals that she has been kidnapped by antiquities smugglers, the cunning cousins Ira and Ralph. With Elaine's life hanging in the balance, she urges Joan to travel to Cartagena, Colombia, armed with the map to secure her sister’s ransom.
Joan's journey takes a harrowing twist when she is intercepted by the treacherous Colonel Zolo, who had earlier invaded her home searching for the map. Misled into taking the wrong bus, Joan finds herself deep in the Colombian countryside, pursued relentlessly by Ralph. Just when hope wanes, she encounters Jack T. Colton (portrayed by Michael Douglas), an American exotic bird smuggler who comes to her rescue, turning the tide of her gripping adventure.
As they traverse the perilous jungle landscape, Joan and Jack evade Zolo's military forces while making their way to a small village. Here, they meet Juan, a drug lord enamored with Joan's novels, who becomes a key ally in their escape from Zolo's relentless pursuit. Joan's writing prowess is put to the ultimate test as she navigates a treacherous real-life saga filled with intrigue, suspense, and unexpected romance.
As the heat of adventure ignites their chemistry, Jack proposes a bold alternative: instead of surrendering the map, they should embark on a treasure hunt of their own. The allure of El Corazón ("The Heart"), a legendary emerald rumored to be worth a fortune, proves irresistible. Under the cloak of night, Jack and Joan commandeer Ralph's car—unbeknownst to them, Ralph is asleep in the backseat. Their escape is frantic, as Zolo's henchmen give chase, leading them through a high-stakes game of cat and mouse and ultimately to the heart of the treasure.
But triumph is fleeting when Ralph awakens and seizes the emerald at gunpoint. With Zolo’s forces swiftly closing in, Jack executes a stealthy maneuver to reclaim the gem amidst the chaos. Separated by the tumult of a raging river, Jack secures the emerald while Joan holds onto the precious map, exposing them both to imminent danger.
Fate guides them to the vibrant streets of Cartagena, where Joan reunites with Ira, only to discover that Zolo has taken Jack captive along with a injured Ralph. In a climactic scene filled with tension, Zolo attempts to inflict harm on Joan, prompting Jack to devise a daring rescue plan involving the emerald and a waiting crocodile.
The plot thickens as Zolo meets his comeuppance when the very beast he sought to manipulate retaliates, delivering a crushing bite that severs his hand and swallows the emerald. Chaos erupts between Zolo's henchmen and Ira’s crew, leaving Joan and Elaine scrambling for safety as the fight ensues.
Eventually, Jack confronts Zolo in a fierce exchange, with Joan proving her mettle against the villain’s wild moves. As law enforcement closes in, Zolo's downfall occurs in a crocodile pit, bringing an end to his reign of terror.
With the dust settling, Joan returns to New York City, channeling her tumultuous experience into a new novel that captivates her publisher, Gloria, to tears, hailing it as a masterpiece. Meanwhile, Jack pursues his dream of owning a sailboat named after Joan’s literary heroine, eagerly awaiting her return on the open waters, ready to embark on a new adventure together, with memories of their perilous journey etched in the fabric of their lives.
