You're a somewhat jaded travel writer on assignment in France. You've just been jilted by your Parisian girlfriend for an unwashed Left Bank philosopher, and you can feel the onset of middle age in your bones. Everything seems gray: You've been all over the world, more or less, and you're considering the possibility that your life's share of adventures has been expended.

Then, as if by providence, while museum-going one day you bump into a fellow American, an aging hippie physicist from California, or rather he bumps into you. You strike up a conversation; he invites you for a coffee. You can't shake the feeling that he knows you, but you don't know him. His story emerges; he has a proposition to make, an offer no self-respecting travel writer could dismiss out of hand.

In his possession, he tells you, is a time machine; yes, a working device to transport its user backward and forward in the fourth dimension. You scoff; you make as if to leave, but something about this man gives you pause. He doesn't seem crazy. And then he proves to you that the thing works.

What does he want from you? Simply this: use the machine to go to a specific place at a specific time - Hollywood, California, in its big-studio heyday immediately before World War II, when Howard Hawks was in his prime and Bogart was still waiting for his break. Find a young Warners contract actor, Ronald "Dutch" Reagan, and do whatever it takes to push him off the path that leads him, forty years later, to the Oval Office. Be ingenious. You'll think of something ....

And so, Gabriel Prince, you sign on for the ride, little knowing just how wild it will prove to be. You wouldn't have guessed you'd fall in love with a starlet, or stumble into a job as a screenwriter, and you certainly wouldn't have guessed that you and Dutch Reagan would become friends. And you'd never have guessed, much as you wish you had, that this time machine you've been provided has a past of its own. If it's taken away from you while you're still in the past, where does that leave you?

What would the world be like if Reagan had never been president? What's a man to do when he has time on his hands.