It's 1960s Detroit and Bob Kearns (GREG KINNEAR) is an applied electrical engineering professor and amateur inventor, happily married to Phyllis (LAUREN GRAHAM) and father to six kids. While driving in the rain one day, he ponders why his windshield wipers couldn't act like the human eye and "blink" away the moisture and in a "flash of genius" moment, comes up with the idea for the intermittent windshield wiper.
After designing a prototype in his basement, he and longtime friend turned business partner Gil Privick (DERMOT MULRONEY) decide to pitch the idea to Ford. That company's technicians are initially skeptical, and Bob is cautious to show them too much lest he let the genie out of the lamp. Nevertheless, various officials there, including Frank Sertin (DANIEL ROEBUCK), are impressed enough that they strike a deal where Ford will use the product that's to be manufactured by Bob's new company.
But just as quickly as they agreed to the deal, Ford suddenly backs out, and it's not long before Bob sees one of their newest models sporting his invention. After hiring lawyer Gregory Lawson (ALAN ALDA) but getting nowhere when Bob refuses any settlement if Ford doesn't admit guilt, he decides to strike out on his own.
Yet, by doing so, and as the months and then years pass, his quest puts a severe strain on his marriage as well as his relationship with his kids who continue growing up without him around. From that point on, and finally winning son Dennis' (JAKE ABEL) support, Bob forges ahead to prove that Ford stole his invention.