It's definitely set in a medieval world with some sci-fi components, like flying "space" vehicles. It's made in the early 90's, and the "medieval" people believes that the sci-fi parts are magic. Watch the trailer: 1:47.
A group of teenagers go on a school camp in the Blue Mountains in Australia. While at the camp, Paul Reynolds accidentally goes into a parallel universe. This other world is inhabited by a more hierarchic and technologically different society, ruled by a group of people known as Spellbinders. Paul meets a girl there named Riana, and they become friends.
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Paul is eventually able to travel back home, but he is forced to take Riana with him in order to save her. Later, when Paul is able to take Riana back home, the Spellbinder Ashka follows Paul as he later returns home. Ashka seeks the unwitting help of Paul's father in making her a new high-tech 'flying suit' to replace her power suit in order to make her more powerful than the other Spellbinders.
However, Paul manages to expose her scheme and defeat Ashka, who is returned as an outcast to the Spellbinder world, while Riana becomes the new apprentice to Correon. In order to keep the Spellbinder world safe from the more advanced people from "modern" world, the gateway between the two universes is closed permanently.
