Kilauea and Mauna Loa anchor this look at what happens beneath a Hawaiian volcano's surface, not just on top of it. Narrator Roger Mudd walks through cutaway diagrams and transparent gelatin models that trace Kilauea's underground plumbing, showing how magma moves from chamber to vent before it ever reaches daylight. The film pairs that with live-action footage of lava fountains and active flows, plus scientists taking measurements in the field, and it reaches back to rare early twentieth-century footage of Thomas A. Jaggar, founder of the Hawaiian Volcano Observatory, working on the volcano himself. Script and geologic advice come from U.S. Geological Survey and Smithsonian researchers, which keeps the explanations tied to actual monitoring work rather than generic volcano imagery. Produced by Maurice Krafft with the Smithsonian and USGS, the film treats eruption not as a single dramatic event but as the visible end of a much longer underground process, and the models are built specifically to make that process visible.