Marvin Flynn read the following advertisement in the classified section of the Stanhope Gazette:

This commonplace announcement was enough to set Flynn's pulse racing. To swap bodies with a Martian… It was an exciting idea, but also a repellent one. After all, no one would want some sand-grubbing old Martian inside his head, moving his arms and legs, looking out of his eyes and listening with his ears. But in return for this unpleasantness, he, Marvin Flynn, would be able to see Mars. And he would be able to see it as it should be seen: through the senses of a native.

As some wish to collect paintings, others books, others women, so Marvin Flynn wanted to acquire the substance of them all through travel. But this, his ruling passion, was sadly unfulfilled. He had been born and raised in Stanhope, New York. Physically, his town was some three hundred miles from New York City. But spiritually and emotionally, the two cities were about a hundred years apart.

Stanhope was a pleasing rural community situated in the foothills of the Adirondacks, garlanded with orchards and dotted with clusters of brown cows against rolling green pastureland. Invincibly bucolic, Stanhope clung to antique ways; amiably, but with a hint of pugnacity. the town kept its distance from the flinthearted megalopolis to the south. The IRT – 7th Avenue subway had burrowed upstate as far as Kingston, but no farther. Gigantic freeways twisted their concrete tentacles over the countryside, but could not take over Stanhope's elm-lined Main Street. Other communities maintained a blast pit; Stanhope clung to its antiquated jet field and was content with triweekly service. (Often at night, Marvin had lain in bed and listened to that poignant sound of a vanishing rural America, the lonely wail of a jetliner.)