Joan Wilder and Jack Colton embark on a quest to steal back the Jewel of the Nile from a power-hungry Sheik and return "it" to the Sufi Arabs, re-vamping their love life and zest for adventure along the way. Joan Wilder (Kathleen Turner) is a famous and successful authoress of romance novels who is having problems regaining the inspiration required to finish her next story. She and her lover, the vagabond Jack Colton (Michael Douglas), have settled into their life on his yacht and everything seems good, though Joan isn't currently interested in getting married. She also feels she can't write because she is stifled by the aimless life she and Jack share together. One day, at a dinner party thrown to celebrate her successful romance books, a wealthy Arab Sheik named Omar convinces her to come back with him to Kadir to write his biography. Joan is mesmerized by the thought of going to visit his beautiful palace and writing powerful political pieces that could make a difference to his ambitions to become a ruler that will unite the Arabic tribes. She and Jack have a lover's spat and she ends up going off with Omar, leaving Jack behind.
Jack is confronted by another Arab man named Tarak who tells him that Omar has stolen the Jewel of the Nile from his people - the Sufi people - and that Joan is likely in danger. Ralph, who is an old enemy of Jack's from the first movie, Romancing the Stone, overhears the mention of potential treasure. His original intention was to find Jack and kill him as revenge since Jack put him in prison, however, at the prospect of treasure, he instead convinces Jack to work with him to steal the Jewel of the Nile and free Joan in the process. When Jack's yacht explodes, he understands the magnitude of his situation as it is likely Omar has planted a bomb to kill or detain Jack and prevent him from rescuing Joan.
Meanwhile, Joan tries to throw herself into her work writing the biographical piece for Omar, however she is disturbed by Omar's brutality and violence towards others in the palace. As she snoops around more, she discovers that Omar is really a power-hungry man who will do anything to paint himself like as a noble and benevolent ruler who is the chosen one to unite and lead the Arab people. She starts trying to take photographs as proof of Omar's true nature, photographing Omar engaging a magician to use special effects to make it seem like he has special powers, which he plans on using in a big-scale performance at a rally in Kadir. Omar soon discovers what she is up to and imprisons her in her room, telling her that Jack is dead. Joan manages to escape and accidentally stumbles into the room of Joe Al Julhara, who is a holy man. She finds out that this holy man is the Jewel of the Nile, and has been kidnapped and imprisoned by Omar because he refuses to give him his blessing as a supreme ruler of the Arab people. Joan helps Joe escape from Omar.
Meanwhile, Jack, Ralph and Tarak arrive at Omar's palace and demand to see Joan. Upon learning that Jack is around, Omar orders his soldiers to kill him. In typical movie-magic fashion, Jack coincidentally ends up finding Joan and Joe as they are escaping (by climbing over the wall of Omar's compound). Joan is relieved and happy that Jack is still alive. They don't have time to talk, however, as Omar has now sent his entire army out to find them. Jack steals a fighter jet and manages to figure out how to use the controls to shoot missiles at Omar's tanks and at his palace, destroying most of it. Jack, Joan and Joe escape in the jet, leaving Ralph behind with Tarak and his small group of Sufi warriors. Tarak thinks that Ralph was in cahoots with Jack to steal the Jewel of the Nile, so Ralph promises that he knows where Jack is going and will help them find the Jewel of the Nile in exchange that they spare his life.
Meanwhile Jack's stolen jet eventually crashes in the desert and Jack, Joan and Joe make the long trek across the desert and into a rocky canyon. They are soon caught up by Omar and his men, who are in tanks. Joan and her group climb up the canyon walls to evade Omar. Enraged, Omar shoots a missile from his tank at the canyon where he spies Joan and her group hiding. This plan backfires, however, as he ends up dislodging boulders that crush his tanks and slow him down further.
Joan and company climb to the plateau where they are confronted by a Nubian tribe. When the Nubians find out that Joan is not married, they declare that they will fight for Joan's hand. Jack fights the muscular Champion of the tribal chief's son, winning only because the Champion was briefly distracted by Joe's antics with his umbrella. After the fight, Jack and Joan express their renewed love for each other and dance at a celebratory Nubian festival. Joan finally tells Jack the truth - that Joe is the so-called Jewel of the Nile. Jack is angry that Joan lied to him and didn't trust that he would have good intentions and still help her and Joe even though there isn't any treasure involved. He still ends up helping Joan, though their relationship is again rocky.
Joan and her group decide to sneak onto a train which will speed their way to Kadir and get them there in time to foil Omar's plans at the upcoming rally. Unfortunately, the train is full of Omar's soldiers. After an action-packed chase above and inside the train carriages, they eventually end up right at the caboose where Omar is having lunch and are captured. Meanwhile, Ralph participates in some Sufi rituals and becomes initiated as a Sufi after he successfully manages to walk over hot coals with the other Sufi warriors.
At Kadir, Joan and Jack are tied up and strung over a pit. Jack's rope is due to break once the rats chew through his bloody rope whereas Joan's rope is due to break once the acid dripping from a spout eats its way through the rope. Omar has apparently come up with this ingenious way of killing Joan and Jack straight out of one of Joan's romance novels. Meanwhile, he and his men make the preparations for the majestic and over-the-top rally which his magician and special effects whiz will coordinate for him. Already, Arabs from across the land have gathered eagerly to see their new leader in all his glory.
Ralph discovers Joan and Jack in their predicament and spends a few brief moments gloating at their troubles before inadvertently freeing them. Joe, who was chained up, is also freed and everyone hurries to the stage to stop Omar. Jack fights off Omar's soldiers while Joan tries to find a way to reach Omar. Meanwhile, Omar has already made his grand appearance by rising up on a crane behind a curtain of fire, as if the flames can't hurt him when really it is just movie magic arranged by his magician. Jack succeeds in disabling the special effects team and there is chaos everywhere. Joan finds her way to the controls of the crane Omar is using to rise above the flames and knocks Omar off the platform, causing a fire in the process. Meanwhile, Joe makes makes his appearance as Al Julhara, the Jewel of the Nile, and much to the astonishment of the Arab people, he walks through the flames towards them. The Arab people cheer and fully embrace Joe as their true spiritual leader.
The movie ends with Omar falling to his fiery death from the platform and Joan and Jack being saved by Ralph who operates a crane to move them to safety. Joan and Jack are officially married by Joe and prepare for their next adventure, sailing away on a sailboat. Though he doesn't get "The Jewel of the Nile", Ralph does end up getting a beautiful jeweled dagger form Tarak to represent his heroism in helping the Sufis get Al Julhara back.
Best part of story, including ending:
I like that this movie follows the life of Jack and Joan after the "happily ever after" of Romancing the Stone (the first movie) and showcased how their relationship is far from perfect and that they still need to work on it to keep the adventure and excitement alive.
Best scene in story:
My favorite scene was when Omar had strung up Jack and Joan above the pit based on a scene from one of Joan's romance novels. It was just another moment to laugh at Joan's silly romance novels and how they always end up getting the two into more trouble than they need.
Opinion about the main character:
I like that this movie showcased a more mature Joan. In the previous movie of the "duology", Romancing the Stone, Joan was a silly, naive woman who is searching for romance. In this movie, Joan has become a more mature woman, able to go on adventures herself and not requiring so much rescuing from Jack.