Famous, but lonely, romance novelist Joan Wilder's (Kathleen Turner) life changes forever the day she receives a mysterious package and ransom demand for her sister. The kidnappers, Ralph (Danny DeVito) and Ira, (Zack Norman) are holding Wilder's sister in Columbia, so Joan must drop everything and take the package to them, in the village of Cartagena. Joan gets lost quickly in a foreign country, not speaking the language and being intentionally misdirected by another person who would do anything to get the contents of the package she carries. Luckily, instead of losing the package, she encounters petty mercenary Jack T. Colton, (Michael Douglas) who agrees to guide her, but for a price. Wilder and Colton butt heads over the best way to save Wilder's sister, but Colton eventually persuades her that by using the package to find the treasure it leads to, they will have a better bargaining chip to save her sister. Wilder is still not sure she can trust the handsome stranger working his way into her heart, but she decides to see it through to the end.