In Berlin in 1961, an American soldier and a German engineer join forces to build a tunnel under the Berlin Wall in order to smuggle out refugees, including the soldier's East German girlfriend.

Richard Thomas
as Sandy Mueller

Horst Buchholz
as Emerich Weber

José Ferrer
as Martin Komansky

Ute Christensen
as Ilse Morrell

Jacques Breuer
as Joachim Lentz

Nicholas Farrell
as Georg Heptner

Kenneth Griffith
as Bruno Balderbach

Robert Freitag
as Dr. Lentz

Gerald W. Abrams
as Phil

Ilse Bahrs
as Butcher Customer