In May 1863, Axel lives in Hamburg, Germany with his uncle, Professor Otto Lidenbrock, who is an eccentric geologist. Lidenbrock shows Axel an old Icelandic book, and a piece of parchment falls out with a coded message written in runes. Lidenbrock becomes obsessed with deciphering the message until Axel stumbles upon the solution by chance. The message is from Arne Saknussemm, a 16th-century Icelandic alchemist, and describes how he traveled to the center of the earth.
Lidenbrock is eager to follow Saknussemm’s instructions to the center of the earth, but Axel has no desire to join his uncle on this dangerous adventure. Lidenbrock believes that the earth’s core is not a burning core of fusion, as is commonly accepted, and he hopes that this journey will prove his theory. Axel, though, does believe in a burning core, and he sees the journey as almost certainly fatal. However, he agrees to accompany his uncle when his fiancée, Gräuben, suggests that the expedition might help Axel grow more independent from his uncle.
Lidenbrock and Axel travel to Iceland, where Saknussemm’s instructions begin. They hire Hans Bjelke, an Icelandic eider-duck hunter, to guide them on the expedition. The three men then travel to the Icelandic volcano Snäffel. They travel down a volcanic chimney and enter a series of subterranean tunnels. Both Axel and Lidenbrock find evidence for their respective theories regarding the earth’s core.
Two days into the journey, Lidenbrock leads the men down the wrong path and refuses to admit his error. They run out of water, and on the way back along the path, Axel faints from dehydration. He begs Lidenbrock to call off the expedition, but Lidenbrock refuses. They continue walking and hear a subterranean spring in the walls. Hans breaks through the wall with a pickaxe, allowing them access to a spring they name the Hansbach in his honor. They follow the Hansbach further down into the earth. Axel loses his way and becomes separated from Hans and Lidenbrock for several days. By the time he reunites with them, Hans and Lidenbrock have discovered a massive underground cavern that contains a forest, ocean, and clouds. It is lit by a “continuous aurora borealis.”
Hans builds the men a raft, and they embark across the ocean. As they sail, they witness a plesiosaurus and an ichthyosaurus (prehistoric marine reptiles) fighting each other amid the waves. A few days into the journey, a hurricane destroys the raft and sends the men back to the shore they set off from. Along the coast, Lidenbrock and Axel discover a collection of fossilized dinosaur bones from the tertiary period, and they discover human bones among them. They continue walking and see a giant man herding a flock of mastodons and mammoths. Lidenbrock and Axel leave without disturbing the giant and find a tunnel marked with Arne Saknussemm’s initials. Axel is excited to find proof that they are on Saknussemm’s path, and he suggests blowing up the rocks that obstruct the tunnel. When they do, the sea rushes into the tunnel to fill the space, pulling the men and their raft down into a seemingly endless abyss. As they fall, the men lose their provisions, leaving them without food.
The raft falls into a waterspout that pushes it upwards. As the raft continues to rise, the men realize they are inside a volcanic chimney. The volcano expels them, and the men find themselves on Stromboli, a volcanic island off the coast of Sicily. After this adventure, Hans returns to Iceland, while Lidenbrock and Axel return to Germany. Lidenbrock achieves glory and esteem in the scientific community, while Axel happily marries Gräuben.
