|Eleanor Parker||Joanna Leiningen|
|Charlton Heston||Christopher Leiningen|
|Romo Vincent||Boat Captain|
|Douglas Fowley||Medicine Man|
Moved by lonely letters written to her brother by cocoa plantation owner Christopher Leiningen, New Orleans widow Joanna agrees to marry Christopher by proxy. Upon arriving at his South American plantation, Joanna clashes with the moody Christopher over his dismay about her previous marriage and the harshness of jungle life. The relationship appears doomed -- until a horde of attacking black ants forces the Leiningens to pull together.