In 1863, German professor Otto Lidenbrock buys the manuscript of an old Icelandic saga. Hidden inside its pages, he and his nephew, Axel, find a coded document written by an Icelandic alchemist named Arne Saknussemm. Decoding it, they discover the runes are directions to the center of the earth. Saknussemm explains that he has successfully made this journey, which makes the professor believe it is possible.

As Saknussemm explains in his directions to the earth’s center, they must first descend through an Icelandic volcano, so the pair immediately head for Iceland. Their only window of opportunity for the journey is late June, which is almost upon them. Axel doesn’t want to go, but Lidenbrock is ambitious and unstoppable.

After they arrive in Iceland, Lidenbrock and Axel hire a guide, Hans Bjelke, who is a duck hunter. As the three men successfully navigate the volcano and travel ever closer to the earth’s center, they encounter many perils, including dangerous flammable gas. Their resources run precariously low, and at one point, they almost perish for lack of water. Once, Axel is temporarily separated from his uncle and the guide, a harrowing experience that leaves him anxious but unharmed.

The center of the earth, though immensely dangerous, is also a wondrous place. It is a huge cavern seemingly untouched by humans from the surface of the planet (though the trio stumbles across the initials “A.S.” carved into a rock). This underground world is lit by electrified gas. The three men encounter giant mushrooms that grow taller than they do and a huge sea, upon which they travel on a raft. They are the first, with the exception of Saknussemm, to enter this place, so all that they see is unknown and undiscovered. As such, they have the privilege of naming the geographical features they find along their journey.

In this fantastic place, they discover evidence of species long extinct in the world above, such as dinosaur bones and living herds of mastodons. They also find human remains, and the explorers are surprised when they see what appears to be a twelve-foot humanoid, though they cannot decide if it is more ape or more human. They don’t want to be seen by this man-ape or disturb him, as they fear what he or his group might do, so they carefully avoid disturbing him or drawing attention to themselves.

Eventually, the men’s path through to the center of the earth is blocked by a rock slide. They try to use dynamite to blast their way through, but this disturbance causes the nearby sea to rush through the hole they’ve created. Their often wondrous, always dangerous journey comes to an unceremonious end as the rushing water carries them up through a mountain until they are ejected to the surface world. When they regain consciousness, they realize that they have surfaced in Italy, after being ejected from the mouth of Stromboli, a volcanic island in the Mediterranean Sea. When they return home, Lidenbrock begins to give lectures on their journey. His work is published with much fanfare, and he is praised by his fellow academics as one of the greatest scientists to ever live.