Near Moab, Utah, mining engineer Larry Kendall (Richard Basehart), is searching for large uranium deposits and joins forces with Katherine Rand (Phyllis Kirk) and her father, Dr. Andrew Rand (Russell Collins). When Dr. Rand is hurt in an accident, Kendall and Katherine continue on, enlisting the help of an Indian guide, Charlie Rivers (Alan Wells). Barnwell finds their location and attacks them, shooting Kathy, and setting off an explosion that seals the entrance to the cavern. Knowing that Charlie has ore samples, Barnwell kills him in an ambush and steals the samples.