Teenager Kathy Morgan, on a family camping holiday with her brother, John, and her parents, Carl and Vicky, is bored. But she gets more than she could have wished for when she comes across a strange-looking craft in the bush. She gets in and fiddles with the controls, accidentally starting it up. As it starts to dematerialise, a strangely dressed man leaps in and her brother, Josh, arrives just in time to see his sister vanish. The boat appears in the Spellbinder World. It is a world where the Industrial Revolution never happened and where a powerful group called Spellbinders control an ignorant population. The man, Mek, explains that he is the inventor of the trans-dimensional boat, which can travel between parallel worlds. Before he can take Kathy home, they are captured by a Spellbinder.
Mek and Kathy are taken to a labour camp, where Ashka, the ruthless Spellbinder, is a prisoner. Ashka persuades Mek and Kathy that they are in danger and promises to help them escape, if they will take her with them. The escape succeeds and Mek takes Kathy and Ashka in the boat to the Land of the Dragon Lord. Kathy is eager to go back to her world, but Mek asks her to stay to help him prove that his boat works. Suddenly, a giant hand appears in the sky and the disembodied voice of the Dragon Lord summons them to the palace.
Kathy is taken before the Dragon Lord. He turns out to be a spoiled ten-year-old boy named Sun, whose seemingly magical powers are provided by an ancient computer, the Oracle. The Dragon Lord takes a liking to Kathy and makes her his royal companion. Realising that he is never going to let her go, Kathy attempts to leave. She and Ashka are discovered as they sneak away from the palace and try to escape in the trans-dimensional boat.
Sun takes the boat to Kathy’s world, where he is chased by the Morgan family in the Jeep. Terrified, Sun returns to the Land of the Dragon Lord with the Morgans close behind him. They all appear outside the border of Sun’s land and are attacked by an army of barbarians. The terrified Morgans drive off. Kathy and Ashka rescue Sun and the Dragon Lord appoints Ashka as his new adviser.
The bewildered Morgan family is caught by an army of barbarians who believe they are spies for the Dragon Lord. Realising she cannot control the Dragon Lord, the ruthless Ashka plots to make Aya, his sister, the new Dragon Lord. Ashka convinces Sun to visit Kathy’s world again and abandons him there. Ashka returns and tells Aya that Sun was eaten by a monster.
Aya is proclaimed the new Dragon Lord and the villainous Ashka is appointed her adviser. Trapped in our world, Sun is frightened, confused and fascinated by all he encounters. Kathy begins to suspect that Ashka may be plotting against Princess Aya and persuades Mek into letting her take the boat back to her world to see if Sun is still alive.
Josh helps his parents escape from Sharak, the barbarian leader, but as they cross the border into the Land of the Dragon Lord, he becomes separated from them. Josh dives into a lake and swims away. In her world, Kathy saves Sun from some larrikins. Kathy discovers that her parents are in Sun’s world but the trans-dimensional boat has been stolen by a film crew. Kathy takes Sun to her home in the city to look for it. Lying exhausted on a beach, Josh is found by a teenage girl, Jasmine. In his wetsuit and fins, she thinks he is a water spirit who will grant her three wishes. Josh tries to escape, but her father thinks he is a monster and threatens him with a spear.
Kathy and Sun trick Kathy’s TV star neighbour, Tony, into helping them find the trans-dimensional boat. Sun’s behaviour makes him suspicious. As Carl and Vicky search for their children, Josh is taken to Jasmine’s village, where he is forced to grant a second wish. He cleverly delays the results, but is kept prisoner in a pond. Tony locates the boat, which is being used in a TV commercial. When Kathy discovers the boat is going to be destroyed as part of the commercial, she has to tell Tony the truth.
Tony creates a diversion allowing Kathy and Sun to get into the boat and escape, just before it is smashed. Kathy and Sun arrive back in the Land of the Dragon Lord, only to find that Ashka is now in command. On the run from Ashka, Kathy and Sun find their way to Jasmine’s village, where Josh is being kept prisoner. When the villagers discover that Josh is not a water spirit, Kathy and Sun save him. But Kathy is caught by Ashka’s men.
Carl and Vicky come to the rescue. They plan to expose Ashka and make Sun the Dragon Lord again. Posing as a troupe of entertainers, they trick their way into the palace. When Aya sees that Sun is alive, she orders Ashka arrested. Ashka flees into the palace and uses the Oracle to make everyone think she has been caught. Then she steals Aya’s jewels and takes the jade interface. The Oracle shuts down, and the Land of the Dragon Lord is left vulnerable. Kathy realises what Ashka has done. She and Mek chase her to the scholastery, where they find the Spellbinder about to escape in the trans-dimensional boat.
Kathy snatches the bag with the interface and jewels from Ashka. They use the boat to escape, but Ashka fires a power bolt, hitting it. Kathy and Mek arrive in a world that is not Kathy’s and realise that Ashka’s power bolt has damaged the boat’s power source. The only way to get home is to repair it. Thwarted, Ashka makes Josh drive her across the border into the barbarian's lands to find Sharak. Meanwhile, Kathy and Mek find a factory run by primitive robots. They fix the power source, but on the way back to the boat, Kathy is caught in a cage. A strange couple, Lem and Guin, take her to their mansion, where Kathy discovers she is the only child in the whole world. She tries to escape but is injured. Ashka and Josh arrive in Sharak’s camp. Sharak recognises Josh from the earlier escape and threatens him.
Ashka saves Josh and tells Sharak she is a magician who can help him invade the Land of the Dragon Lord. Josh uses his mother’s computer and digital camera to make Sharak think Ashka can predict the future. Sharak makes a deal with Ashka. Lem and Guin take Kathy to Doctor Elvo, who tells Kathy that all the people in this world are immortal and infertile, as a result of taking the cure for a deadly plague hundreds of years ago. Elvo promises to find Mek and help Kathy escape. Meanwhile, Vicky tries unsuccessfully to repair the Oracle. Lem and Guin show Kathy off to their friends. Hugo, another immortal, tries to kidnap Kathy. The arbiter is summoned to sort out the owner ship dispute. Kathy tries to prove she has come from another world, but the trans-dimensional boat has gone.
The Arbiter declares that Lem and Guin are legally Kathy’s parents and orders that she be educated in the ways of this world. In the Land of the Dragon Lord, Sharak and his army arrive at the border river crossing. Ashka pretends to cast a spell, clearing the way for the invasion, then forces Josh to cross the river first. When nothing happens, the army rushes into the river. Josh runs for his life. Josh arrives in Jasmine’s village to warn her of the invasion, but is recognised as the water spirit and captured. Meanwhile, Kathy is continually questioning her educators in the Immortal World. This creates an uproar and in the ensuing chaos she manages to escape. Hugo follows her and tries to kidnap her again, but Guin saves her. The Arbiter decides that the only way to keep the immortals happy is for Kathy to be shared. But the only way to do this is to make her immortal too. Kathy is taken to an ancient hospital and is about to be injected with the immortality serum.
In the Immortal World, Doctor Elvo saves Kathy and tells her he has found Mek. But he is not allowed to take her. Kathy must go with Lem and Guin. Kathy disguises herself as a robot and escapes. She goes to Elvo’s, but he imprisons her with Mek. Elvo tells the horrified pair that he is going to use them to breed a whole new generation of children. In the Land of the Dragon Lord, the barbarians now occupy Jasmine’s village. Jasmine helps Josh escape but is caught. Josh heads for the palace. Josh arrives at the palace and warns of the invasion, but without the Oracle, things look hopeless. Josh suggests they try to trick Sharak into thinking the Oracle still works. Ashka, Sharak and the army arrive at the palace. The Morgans, Sun and Aya use fireworks and the Jeep to trick Sharak, but Ashka foils the plan. Sharak threatens to hurt Sun, unless Aya surrenders.
Aya surrenders and the barbarians take over the Dragon Lord’s palace. Josh and Vicky evade capture. They rescue Sun, but Vicky is caught. Kathy and Mek escape from Elvo’s laboratory and go to the factory where Elvo has hidden the boat. Elvo gets there first and smashes some of the boat’s delicate mirrors. The Arbiter and more immortals arrive. Guin and Lem finally realise what being a parent means and help Kathy and Mek get away. Kathy and Mek arrive in a world of water and no land. They have no choice but to try and get the damaged boat to another world. Hiding in the secret passages inside the palace, Josh and Sun overhear that Sharak is planning to force Aya to marry him and become the new Dragon Lord.
Kathy and Mek arrive in another world inside a huge building that looks like a scrap yard. While looking for some replacement mirrors, they find a huge, tank-like machine. Mek decides to try and get it working to make the mirrors. Kathy goes in search of food. To stall the wedding, Josh and Sun make Sharak think that Sun is dead. Then they fool him into believing he is being haunted by Sun’s ghost. Kathy finds a village, where meets she Jez, a teenage boy. He and the villagers have been living underground until recently. All machinery is forbidden. Then Kathy discovers that the machine Mek is repairing is a molloch, a killing device programmed to destroy all human life. Kathy tries to stop Mek but is too late. The molloch comes to life and attacks.
Mek tries to get back into the Molloch but is hurt. The molloch goes after Kathy. Jez takes Kathy into a hut which hides an entrance to a mine. The mollach demolishes the hut and Mek thinks Kathy has been killed. Carl takes Ashka to Jasmine’s village, where she stops an angry confrontation between the villagers and the barbarians. Ashka tells them they must live together. Then Ashka discovers that Sharak is planning to marry Aya. Josh and Sun continue to haunt Sharak to stall the wedding. Jez takes Kathy into the mine where the villagers lived when they were hiding from the mollochs. But the molloch sends smaller machines down into the tunnels to hunt the villagers. Kathy uses an old, mirrored shield to deflect a laser beam and destroy one of the smaller machines. She saves Jez but is knocked out. When Kathy awakens, she finds she has been taken deep into the mines and the villagers are about the blow up the tunnel, trapping her underground.
Kathy escapes from the tunnel but is chased by another, smaller machine. Jez saves her and takes her to the surface. The village has been completely destroyed by the molloch. Jez vows to destroy it. Mek is relieved to find Kathy alive. Kathy thinks up a plan to get inside the molloch and disable it using one of the small machines as a Trogan Horse. She is the only one who will fit inside it. Josh and Sun continue their haunting, but Ashka discovers them and chases them through the secret tunnels in the palace. Kathy’s plan succeeds and she gets inside the molloch. But it sees the trans-dimensional boat. Jez tries to divert it away. Kathy disables the molloch just before it crushes Jez. Mek repairs the boat and he and Kathy leave, promising Jez they will come back and help as soon as they can. Kathy and Mek arrive back in the Land of the Dragon Lord, but before they can get to the palace, they are captured by barbarians. Josh and Sun are hiding in the Oracle chamber, trying to think up another way to stop the wedding, when Ashka finds them.
Ashka takes Sun prisoner, but Josh escapes. Ashka tells Sharak that if he marries Aya, She’ll marry Sun. Then they’ll both be Dragon Lords. Sharak is furious. Word of Kathy and Mek's capture reaches the palace, just as Sharak tries to kill Ashka. Aska takes the boat to Kathy’s world, but is stranded when some kids meddle with the boat controls, sending it back to the Land of the Dragon Lord. Kathy and Mek are taken to the palace where Kathy’s parents, Sun and Aya are prisoners. Josh masterminds an escape, but just as it seems they have got away, Vicky is captured. Kathy and Josh are forced to leave their mother behind.
Carl gets himself captured, allowing Kathy and Josh to take the trans-dimensional boat back to their world. Sun and Aya go to Jasmine’s village to hide. Kathy and Josh track Ashka down and discover she intends to sell the jewels and interface to an antique dealer called Bain. They try to snatch the bag, but are chased by the Police. In the Land of the Dragon Lord, Sun and Aya arrive at Jasmine’s village, but are spotted and chased. Jasmine helps them get away - but it's only a temporary reprieve. They have to find a way to convince the barbarians that they have left the village. When Kathy arrives at her house, her neighbour, Tony, treats her as if they have hardly spoken. Then Kathy sees Josh and he too is acting strangely. Kathy hears a familiar voice and looks through a window into her house. She is shocked when she sees – herself!
As Kathy watches her parallel family, she realises that slight damage to the boat has bought them to another parallel world – one where a Morgan family already exists. In this world, her parents are divorced and her parallel father is the host of a TV sports show. Jasmine helps Sun and Aya trick the barbarians into believing that they have sailed away from the village. Then, Jasmine takes Sun and Aya to her house, where her father, Den, gives them shelter. Kathy and Josh convince Tony to take them to the antique dealer’s shop. But Ashka doesn’t have the jewels and the interface. They follow her and Bain to a cemetery and discover that Ashka has hidden the valuables in a crypt. Bain drugs Ashka and locks her in the crypt with Kathy and Josh. Jasmine convinces her father, Den, and Gobbo, the barbarian who is sharing their house, to forget their differences and work together to plant a new crop of rice. Josh tries to use Ashka’s power suit to blast open the crypt door. He fires a power bolt but it hits him instead. Josh collapses, unconscious.
Ashka regains consciousness and uses the power suit to break out of the crypt. Kathy makes Ashka agree to work with them - They’ll get the interface and Ashka can have the jewels. Sun, Aya, Jasmine, Den and Gobbo’s family are working in the fields. Den is forced to tell the village Elder who Sun and Aya are. Word quickly spreads. Kathy, Josh and Ashka find Bain’s shop abandoned. The trail is cold. They pretend to be their parallel selves and ask the parallel Carl for help. He gets Bain’s address, but the house is empty and for sale. Kathy and Josh use the real estate agent to track Bain down to a yacht club, but don’t know which of the many yachts is his. Roggar, Sharak’s lieutenant, bursts into Jasmine’s house and arrests Aya. He orders the house searched for Sun. Gobbo is shocked to discover that his two young daughters are hiding Sun. Will he give the boy away?
Aya is taken to the palace for the wedding and Sun and Jasmine decide to rescue her. Kathy, Josh and Ashka locate Bain’s yacht, but it is guarded. Josh goes back to Ashka’s hotel to get the power suit, but runs into his parallel mother. Confusion reigns when she makes him come home with her. When the yacht is left unguarded, Ashka and Kathy sneak on board. Ashka finds the jewels but is caught. Kathy manages to get away. Josh meets his parallel self and enlists his help. They hurry to the yacht with the power suit. Thinking that Kathy and Ashka have been captured, they sneak on board, but are locked in a cabin.
Sun and Jasmine try to rescue Aya from Roggar but the attempt fails and Sun goes on the run. The two Joshes make contact with Kathy and she goes to her parallel father for help. She convinces Carl-2 (her parallel father) of her story and they go to Bain’s yacht. Carl-2 uses his reputation to get on board and free the two Joshes. Kathy frees Ashka, but she takes the jewels and interface and escapes. Bain and his men try to force Carl-2 to tell them where Ashka has gone but Josh-2 uses the power suit to blow them into the water. Ashka returns and gets them away. She gives Kathy and the two Joshes a ride to the trans-dimensional boat, but Ashka turns up and tries to steal it. Josh-2 foils her again. Kathy and Josh take the boat back to the Land of the Dragon Lord, only to find that Sun is about to be caught.
Kathy and Josh rescue Sun, who tells them the wedding is at sundown. They will never get back to the Palace in time! They take the boat back to Carl-2’s world and get him to take the boat by trailer to the place in this world where the wedding would be. Ashka follows them and jumps into the boat, just as it leaves. The boat arrives outside the palace and Ashka is caught. The others take the boat back to Carl 2’s world. They move the boat again and reappear inside the palace. Kathy and Josh follow Sharak and discover where Mek and their parents are being held. They free Mek, and Josh takes him into the secret passages. Before they can get to the Oracle, Josh is caught by two barbarians.
Mek rescues Josh by pretending to be Sharak’s violent brother. The two hurry to repair the Oracle. With time running out, Kathy comes up with a desperate plan to buy them more time. She and Aya make a deal with Ashka. The wedding commences but when Sharak lifts his bride’s veil, he discovers it is Ashka! The Oracle is restored and Aya demands that Sharak surrender. Ashka’s evil plan is thwarted and order is restored to the Land of the Dragon Lord. Sharak tries to escape, but Kathy clearly foils him. Kathy and Mek remember their promise to Jez and arrange for the invaders and their families to be transported by trans-dimensional boat to Jez’s barely-populated world, where they will be welcomed. The villainous Ashka is left abandoned in a desolate world. The Morgans return to their world and Kathy says a last goodbye to Sun. Kathy is at the bus stop, comparing holiday experiences with her girlfriends when Tony drives up and offers her a lift in his sports car. Kathy smiles as her envious friends watch her drive away.