After years of experimentation, Dr. Sebastian Caine (Bacon), a brilliant, but arrogant and egotistical scientist working for the defense department, has successfully transformed mammals to an invisible state and brought them back to their original physical form. Determined to achieve the ultimate breakthrough, Caine instructs his team to move on to Phase III: human experimentation.
Using himself as the first subject, the invisible Caine finds himself free to do the unthinkable. But Caine's experiment takes an unexpected turn when his team can't bring him back. As the days pass, he grows more and more out of control, doomed to a future without flesh as the Hollow Man.