Government officials discover a horrible plot: the Chinese are tunneling their way to the United States.
Kerwin Mathews | Cmdr. Jonathan Shaw |
Viviane Ventura | Tila Yung |
Robert Ayres | Adm. Felix Hillebrand |
Peter Arne | Arnold Kramer |
Al Mulock | Sgt. Marvin Mulberry |
Martin Benson | Gen. Chan Lu |
Peter Elliott | Dr. Kengh Lee |
Earl Cameron | Sgt. Seth Hawkins |
John Brandon | Maj. Frank Cannon |
Ed Bishop | Lt. Cmdr. Vance Cassidy (as Edward Bishop) |
Bill Nagy | Col. Talbot Wilson |
Sarah Brackett | Meg Webson |