The Magnetic Monster

Jeffrey Stewart and Dan Forbes, agents of the Office of Scientific Investigation, investigate a mysterious magnetic field at a hardware store, tracing it to an airborne flight carrying scientist Howard Denker, who is dying from radiation poisoning. Denker has brought a new radioactive element, dubbed "serranium," which grows exponentially by absorbing energy from surrounding metallic objects. If not destroyed, the substance could grow large enough to throw Earth out of its orbit within 24 hours.