Franklin Schaffner's film has a rather florid story based on a novel by Ira Levin of unregenerate Nazis led by the real-life villain Dr. Josef Mengele (Gregory Peck) hiding out in Paraguay and plotting to take over zee Vorld (again). Aging Nazi-hunter Ezra Lieberman (Laurence Olivier) and his sister (Lili Palmer) have other plans however.
Evidencing the period's fondness for exotic conspiracy theories (and international air travel, then relatively exotic), the plot is rather fantastic (although our contemporary enthusiasm for genetic engineering shows how quickly we have forgotten the Nazi fondness for this technology) and at times is so caricatural with its depiction of nasty Nazis that one cannot help but recall Kenneth Mars in The Producers.
Of the top drawer cast, James Mason was either feeling his years or was just plain embarrassed to be in such pulp but Gregory Peck, playing against his familiar good-guy persona, is wonderfully over-the-top as the psychopathic Mengele, whilst Olivier who was Oscar-nominated but did not win, turns in a fine performance as his indefatigable opponent.