On a quest to find out what happened to his missing brother,a scientist,his nephew and their mountain guide discover a fantastic and dangerous lost world in the center of the earth.Professor Trevor Anderson receives his teenager nephew Sean Anderson.He will spend ten days with his uncle while his mother,Elizabeth,prepares to move to Canada.She gives a box to Trevor that belonged to his missing brother,Max,and Trevor finds a book with references to the last journey of his brother.He decides to follow the steps of Max with Sean and they travel to Iceland,where they meet the guide Hannah Ásgeirsson.While climbing a mountain,there is a thunderstorm and they protect themselves in a cave.However,a lightening collapses the entrance and the trio is trapped in the cave.They seek an exit and falls in a hole,discovering a lost world in the center of the Earth.When Trevor opens the box of stuff belonging to his lost brother,he pulls out an odd wooden item,declares that he doesn't know what it is,and sets it aside.The item is a Holmes Stereoscope,a device designed in 1861 by the American physician and writer,Oliver Wendell Holmes,for the viewing of so-called "stereocards".A stereocard is like a postcard which has a Left-view and Right-view photograph mounted alongside one another.When viewed through this stereoscope,the photographs are merged into one 3-D image (which was later adopted for the ViewMaster viewers and cards).The Holmes Stereoscope was a great source of entertainment in the Victorian era.It was,in a sense,the Home Entertainment Centre of its day,as it transported its users to exotic places all over the world.People bought packs of stereocards for their entertainment - in much the same way as we buy DVDs today!(Thus,a character in a 3-D movie having no idea what a stereoscope is,makes for a cute little 3-D in-joke...) Continuity:Backpacks tend to reappear at certain important plot turns and such.For example; when they first discover the world at the center of the earth,they throw away their backpacks and continue on without them,then,however,they reappear again prior to leaving on the raft and then while on the raft they are gone once more only to reappear once again prior to meeting the dinosaur.As for Sean's backpack,it is clearly missing when he is jumping the floating rocks and then at the end it reappears when they have landed the dinosaurs skull in Italy.Furthermore,no one is seen carrying an extra backpack at any time,maybe suggesting that the other two carry Sean's pack.