The Cryptic Parchment
Professor Otto Lidenbrock, an eccentric mineralogist, finds an old Icelandic saga. Inside, he discovers a cryptic parchment in runic script. He tries to decipher it, but fails, frustrating both him and his nephew, Axel. The Professor becomes obsessed, neglecting his work and meals. Axel, more cautious, watches his uncle's growing fixation with concern, knowing any discovery will lead to a grand, likely dangerous, adventure.
The Alchemist's Secret
After days, Axel accidentally finds the key to the runic cipher. While fanning himself with the parchment, the Latin message becomes clear. It is from Arne Saknussemm, a 16th-century Icelandic alchemist, detailing his trip to the Earth's center through a volcano in Snaefellsjökull, Iceland, and providing directions. Terrified, Axel tries to keep it secret, fearing his uncle's decision to go. However, the Professor quickly gets the truth from Axel, and his excitement is immense.
Preparation for the Descent
Professor Lidenbrock, now convinced of Saknussemm's claims, immediately prepares for the journey. He tells Axel they are leaving for Iceland, despite Axel's attempts to stop him. The Professor is firm, dismissing Axel's scientific arguments about the Earth's molten core as mere theory, favoring Saknussemm's account. He gathers equipment: instruments, weapons, ropes, provisions, and a new explosive. Axel, resigned, helps with the arrangements, dreading the dangers ahead.
Arrival in Iceland
The Professor and Axel travel by ship from Hamburg to Copenhagen, then to Reykjavik, Iceland. They arrive to a stark, volcanic landscape and unique culture. Their first task is to find a guide to Snaefellsjökull. They meet Hans Bjelke, a stoic eider-hunter known for his strength and efficiency. Hans agrees to go, his calm contrasting with the Professor's enthusiasm and Axel's apprehension.
Ascending Snaefellsjökull
With Hans leading, the trio begins the climb up Snaefellsjökull. The journey is hard, over rugged terrain, lava fields, and glaciers. Axel struggles physically and with growing anxiety, but the Professor remains determined. Hans, with his knowledge of the land, navigates the slopes easily. They reach the summit, a desolate peak, where the three chimneys from Saknussemm's parchment await.
The Descent Begins
At the summit, the Professor searches for the correct chimney, following Saknussemm's instructions: the shadow of Scartaris must fall on the opening at noon on the last day of June. After a tense wait, the shadow points to the opening. Without hesitation, the Professor, then Axel and Hans, descends into the dark shaft. The start is terrifying as they lower themselves with ropes, lanterns lighting the unknown. Axel's fear is clear, but the Professor's drive pushes them on.
Lost in the Labyrinth
As they go deeper, the explorers find a maze of passages. At a crossroads, Professor Lidenbrock chooses a path that leads them astray, despite Axel's doubts. They wander for days, provisions dwindling, and water running low. Axel suffers from thirst and exhaustion. The Professor, though outwardly strong, shows worry. Hans plans to search for water by listening for springs, but the situation becomes serious, threatening the expedition.
The Underground Sea
Just as they despair, Hans finds a hidden stream, providing much-needed water. Refreshed, they continue their descent, entering a huge cavern. Before them is a vast, illuminated underground sea, with a stormy horizon. This confirms Saknussemm's accounts and excites the Professor. The air is warm and humid, and strange, phosphorescent light reveals a unique ecosystem. They name it the 'Lidenbrock Sea'.
Sailing the Subterranean Ocean
To cross the Lidenbrock Sea, Hans builds a raft from petrified wood. The trio sails across the dark waters. They see incredible things, including an electrical storm and a battle between prehistoric marine reptiles – an ichthyosaur and a plesiosaur – a terrifying glimpse into a lost world. Axel is both amazed and scared, while the Professor records every observation. The sea's vastness makes them feel small.
Signs of Humanity and a Critical Discovery
After days of sailing, a storm shipwrecks them on a sandy shore. Exploring, they find a forest of giant mushrooms and ancient plants and animals. More surprisingly, Axel finds a graveyard of mastodons and, carved into a rock face, the initials 'A.S.' – Saknussemm's signature – confirming his earlier passage. Nearby, they also find a rusted dagger. They locate another passage deeper into the Earth, marked by Saknussemm, but a large boulder blocks it, creating a new challenge.
Dynamite and a Volcanic Ascent
Faced with the boulder, Professor Lidenbrock decides to use dynamite. Despite Axel's fears of collapsing the passage, Hans carefully sets the charge. The explosion clears the way but causes an earthquake and a flood of boiling water. The explorers are swept away, descending deeper. They enter a narrow shaft where the water rises due to volcanic activity. They realize they are being carried upwards by an impending eruption, their journey to the center reversed.
Eruption and Return to the Surface
The upward journey inside the volcanic chimney is terrifying, with molten lava threatening them. The heat is unbearable, and they are violently tossed by the rising magma. After a harrowing ascent, they are ejected from the volcano's crater, not in Iceland, but on Stromboli, an active volcano in Sicily, Italy. They emerge disheveled but alive, having traveled across the Earth's interior in hours. Local villagers are astonished. The Professor, though he did not reach the absolute center, is thrilled by their survival and discoveries.
Fame and Reflection
News of their journey spreads, and Professor Lidenbrock, Axel, and Hans become celebrities. They return to Hamburg to a hero's welcome. The Professor publishes his findings, initially met with skepticism, but his detailed accounts and their survival slowly convince doubters. Axel, changed by the experience, marries his beloved Graüben and leads a more adventurous life. Hans, after his payment, returns to Iceland. The expedition, though not reaching the Earth's core, challenges existing science and leaves a lasting mark.