After physicist Dr. Addison (Gene Barry) discovers that his son, Tommy (Lee Aaker), has been kidnapped, he and his wife, Martha (Lydia Clarke), receive a series of telegrams with instructions. The kidnappers want atomic secrets in exchange for Tommy. Although the desperate Addison considers the proposal, he decides to trust the case to an FBI agent, Harold Mann (Milburn Stone). Mann and fellow agent Russ Farley (Michael Moore) attempt to track down the boy and his elusive kidnappers.