Paul Birch walked off the film before shooting was completed after having a physical confrontation with Roger Corman. He was quoted as saying, "I am an actor, and I don't need this stuff... To hell with it all! Goodbye!" According to co-star Beverly Garland, Birch objected to the fast pace of the film, the old-fashioned, uncomfortable hard plastic contacts he had to wear, and the film's low budget, which he considered beneath his status. As a result, Birch's remaining scenes were shot with Lyle Latell doubling for Birch.
According to star Beverly Garland, both interiors and exteriors were filmed in a beautiful old Tudor-style house in Hollywood with a swimming pool.
For the television release in 1963, to make the movie longer, a prologue was written by director Herbert L. Strock and added to the beginning right after the credits. The prologue read: "You are about to adventure into the dimension of The Impossible! To enter this realm you must set your mind free from earthly fetters that bind it! If the events you are about to witness are unbelievable, it is only because your imagination is chained! Sit back, relax and believe.. so that you may cross the brink of time and space.. into that land you sometimes visit in your dreams!" Besides the added prologue, some scenes from the movie were repeated throughout the film to make it appear longer.
One of the bums is played by Hank Mann, one of the original Keystone Kops. At the time he made this, his career had spanned about 45 years and many shorts and features..
When Jeremy is lugging the trunk around for Johnson, he asks, "What do you got in here - King Farouk?" Jeremy is referring to King Farouk of Egypt, who had been living in exile since 1952, when he was overthrown.