Robert Lansing plays a scientist whose brother is trying to perfect a way to make solid objects pass through each other. Lansing finds out about his brother's radical concept and tries some experiments of his own. He succeeds so well that he takes the idea a step further: he makes himself pass through solid objects.
The process has an adverse affect on his mind, and he starts walking through the walls of banks at night, stealing the cash. Unfortunately, the use of his new power causes him to age rapidly, and the only way he can rejuvenate himself is to absorb life-energy by passing through another human being -- even though this kills the victim.
Robert Lansing's performance is quite good, and so are those of co-stars Lee Meriwether and Patty Duke (age 12). Robert Strauss ("Stalag 17", "The Seven Year Itch") is sadly miscast as an unscrupulous fellow scientist. Director Irvin S. Yeaworth, Jr. created a good film on a meager budget, just as he did with "The Blob".
The special effects are impressive (and in color), devoid of any cheap "see-through" superimposed images. Whenever Lansing walks through a wall, he looks like he's stepping into an opaque liquid. Watch for an eerie scene in which Lansing walks slowly across a room towards an intended victim, passing through tables and chairs.