Classic early Hammer sci-fi horror. Two scientists have been working on a revolutionary matter duplication machine, a 'reproducer' that can replicate any object. In celebration Robin (John van Eyssen) announces that he is going to get married to Lena (Barbara Payton), not knowing that his assistant Bill (Stephen Murray) is secretly in love with her. With Lena's uncertain co-operation, Bill decides to duplicate her using the 'reproducer'. At first the experiment seems a success, but then the duplicate Lena is a little too accurate - she falls ni love with Robin as well. Soon Bill is thinking of ever more devious ways to ensure that the new Lena is his alone.