In 1880 Edinburgh, Professor Sir Oliver Lindenbrook, James Mason, a renowned geologist at the University of Edinburgh, receives a remarkable gift from his admirer, a gifted young student named Alec McEwan, Pat Boone. Alec is openly in love with Lindenbrook’s niece Jenny Lindenbrook, Diane Baker, and his gift—a heavy piece of volcanic rock—carries more than meets the eye. Inside the rock rests a plumb bob with a cryptic inscription left by Arne Saknussemm, a scientist who, almost a century earlier, is said to have found a route to the center of the Earth by descending into the volcano Snæfellsjökull in western Iceland. After deciphering the inscription, Lindenbrook and Alec are consumed by a shared sense of wonder and the urge to follow in Saknussemm’s footsteps.
The discovery quickly draws in others. Professor Göteborg, Ivan Triesault, racing to outpace anyone who might claim the feat, becomes a dangerous rival. Lindenbrook and Alec pursue him to Iceland, where tensions rise and danger follows. Göteborg and his assistant seize Lindenbrook and Alec and trap them in a cellar, hoping to undermine their mission. They are eventually freed by Hans Bjelke, Peter Ronson, and his loyal pet duck Gertrud. The grim truth unfolds when Lindenbrook finds Göteborg dead in his hotel room, with crystalline traces of potassium cyanide in his goatee—murder, not accident, has altered the course of the expedition. Carla Göteborg, Arlene Dahl, the widow who once believed her husband’s work would be misused, comes to understand the seriousness of the discovery. She insists on joining the expedition and provides the essential gear her husband had accumulated, including prized Ruhmkorff lamps, but only on the condition that she accompany the team to protect her husband’s reputation. Lindenbrook reluctantly agrees, and Hans and Gertrud join the perilous journey as well.
On a carefully chosen date, the group marks the exact location where the sunrise will align with Snæfellsjökull and begins their descent, following Saknussemm’s ancient markings. They are not alone on this descent; Count Saknussem, Thayer David, a direct descendant who believes he alone has the right to claim Saknussemm’s legacy, trails the expedition with a loyal servant. When Alec becomes separated from the others, he encounters the count, who demands that Alec serve as a replacement for a dead servant. Alec refuses, and the count shoots him in the arm. Lindenbrook tracks the gunshot through echoes, and a quick, controversial trial for murder ensues; Saknussem is condemned to death, but no one is eager to execute him, so the count is reluctantly allowed to accompany them.
Deep beneath the Earth, the explorers reach a subterranean ocean and fashion a raft to cross it. They narrowly escape a family of enormous dimetrodons, and their raft is pulled into a dangerous mid-ocean whirlpool. Lindenbrook theorizes that they have reached the planet’s center, where magnetic forces from the Earth’s north and south poles converge with such intensity that even gold in rings and fillings can be drawn away by the pull. Exhausted but determined, they finally reach the opposite shore.
The nightmare intensifies when Saknussem betrays them by killing Gertrud. Hans discovers the character’s treachery, and in a grim turn of events, Saknussem is crushed beneath a collapsing column of stones, dying as the group moves forward. Behind the ruins lies the sunken city of Atlantis, and the skeleton of Arne Saknussemm points toward a volcanic chimney that seems to lead to the surface. A powerful updraft suggests a fast escape, but a massive rock blocks the path. Lindenbrook uses gunpowder left by Saknussemm to blast the obstruction, and the party takes shelter in a large sacrificial altar bowl. A ferocious lizard attacks but is buried under a flood of lava released by the blast. The altar bowl is driven upward by a torrent of lava and finally reaches the surface, ejecting the explorers away from the eruption’s fury.
Back in Edinburgh, the group is welcomed as heroes, though Lindenbrook refuses to publish their full, documented evidence for fear of compromising their reputations and their university. He encourages future generations to pursue knowledge with wisdom and humility. In the wake of their ordeal, Alec and Jenny marry, while Lindenbrook and Carla share a kiss, signaling their own hopeful future together. The adventure ends with a quiet conviction: the thrill of discovery should inspire awe and responsibility in equal measure, inviting new explorers to step into the unknown with courage, curiosity, and respect for the past.
