Crack in the World 1965

An international consortium of scientists, operating as Project Inner Space in Tanganyika, Africa, is driven by a bold goal: tap the Earth’s geothermal energy by drilling a very deep hole that reaches toward the planet’s core. When their drill meets an exceptionally dense barrier, the team resolves to detonate an atomic device at the bottom in a race against time to punch through.

The project’s leader, Dr. Stephen Sorenson, [Dana Andrews], who is secretly dying of cancer, believes the device will burn its way through the barrier and unlock the energy below. But the team’s chief geologist, Dr. Ted Rampion, [Kieron Moore], argues that decades of underground nuclear testing have weakened the lower crust, and that detonating there could unleash a colossal fracture that might threaten the entire planet.

Their experiment goes forward, and Rampion’s fears are borne out as the crust splits into a vast crack that races along a fault, triggering earthquakes and tsunamis along its path. Rampion warns a global committee that the crack could extend beyond the fault, potentially encircling the world and pulling the landmasses apart, forcing oceans to boil into steam under immense pressure and threatening to tear Earth itself asunder.

Meanwhile, Sorenson uncovers a hidden reservoir of hydrogen beneath the surface, which turns the modest blast into a massive thermonuclear explosion—millions of times more powerful than intended. In a desperate bid to halt the advance, another device is lowered into the magma chamber of an island volcano that sits in the crack’s path, but this intervention only redirects the fracture rather than stopping it. As the fissure nears the test site, a monumental portion of the planet outlined by the crack appears doomed to be hurled into space.

Sorenson remains at the underground control center to record the cataclysm, even as his wife Maggie Sorenson, [Janette Scott], pleads with him to evacuate along with the rest of the staff. The two barely escape the site in time to witness a spectacular, perilous event—the fiery birth of a second moon. That moon’s emergence alters the trajectory of the crack and offers a fragile chance for Earth to endure the crisis.