By the mid-1960s, Americans have developed a taste for fast, delicious, affordable food — and they’re demanding more. U.S. fast food franchises — McDonald’s, Burger King and Burger Chef — know that if they want to feed America and win the burger wars, they’re going to have to grow. But Wall Street is still reluctant to invest in a bunch of burger chains. And Ray Kroc is about to learn firsthand that those who can’t stand the heat need to be forced out of the kitchen.