 Martin has transformed his duplicating machine to have the duplicates become permanent instead of just temporary. He unfortunately duplicates Tim. So Martin goes off to get a mineral needed to eradicate the duplicate Tim, leaving the two Tims to fend for themselves. The real Tim has a great idea: he will get the duplicate to go off to work, while the real Tim goes on a beach date. However the duplicate Tim has other ideas. He uses Martin s personality changing machine on himself to transpose himself into an evil Tim, one that takes the real Tim s money, takes the real Tim s girl, wants to expose Martin s Martian identity to the world, but most importantly wants to take the real Tim s life by proving he s the original and not the duplicate. Things are complicated by the presence of George, Mrs. Brown s psychologist nephew, who is snooping around. With George s inadvertent help, the duplicate Tim tries to sell the entire story to a magazine. Tim gets down to the magazine s office just in time possibly to thwart the deal. But just as the duplicate almost convinces the publisher that that was the "duplicate" that thwarted the deal, Martin shows up. Now Martin has to figure out which Tim is which and which Tim needs to go.