This was originally intended as a starring vehicle for Robert Redford and George Segal at 20th Century Fox, as a sequel to The Hot Rock.
Screenwriter Wendell Mayes was very disappointed with this film and pinned the blame on director Gower Champion, who had, he claimed, imposed entirely the wrong style on the subject-matter.
Most of character names have been changed from the original novel; only Hermann X's name is unchanged.