Spies hold the son of a nuclear physicist (Gene Barry) hostage in exchange for the Los Alamos bomb formula.

Gene Barry
as Dr. Frank Addison

Lydia Clarke
as Martha Addison

Michael Moore
as Russ Farley

Nancy Gates
as Ellen Haskell

Lee Aaker
as Tommy Addison

Milburn Stone
as Insp. Harold Mann

Bert Freed
as Emil Jablons

Frank Cady
as F.B.I. Agent George Weinberg

Houseley Stevenson Jr.
as 'Greg' Gregson

Leonard Strong
as Donald Clark