Government officials discover a horrible plot: the Chinese are tunneling their way to the United States.
as Cmdr. Jonathan Shaw
as Tila Yung
as Adm. Felix Hillebrand
as Arnold Kramer
as Sgt. Marvin Mulberry
as Gen. Chan Lu
as Dr. Kengh Lee
as Sgt. Seth Hawkins
as Maj. Frank Cannon
as Lt. Cmdr. Vance Cassidy (as Edward Bishop)
as Col. Talbot Wilson
as Meg Webson
as Dr. Arnn
as Maj. Chai
as Bomb Train Commander
as Dr. Galissi
as Susan Kramer
as Broadcaster
as Matron
as Matron's Friend
as Lanchek
as Mine Foreman
as Police
as Police
as Nurse
