Dorothy thinks a lot about probability, about the fact that there must be several other young people in her situation. Figuring out how many was a project she performed in fits and starts whenever they had internet and Dad wasn’t monopolizing the computer.

She started with the number of men in America, 49 percent of the population, 160,194,191 men. Then the percentage of men with children: 47 percent, and that brought her down to 75,291,270.

It wasn’t necessary that the men be unmarried. Dorothy’s own father is perpetually single, her mother a gray, sparking patch on the surface of her life, like a video game glitch. But Dorothy doesn’t define herself by her motherlessness. A sibling, however, would have altered the shape of her world. The percentage of only children is 23, and that brings her to 17,316,992.

Dorothy did her math with a pad of paper. Calculators are for cheaters.

It got trickier once she had the only children. Then Dorothy had to figure out how many people lived in RVs full-time. The only number she could find was 260,000, and it was old. But she wasn’t giving up, so she figured out what percentage 260K was of the whole population. 0.08 percent. If Dorothy assumed that living in an RV had no effect on how many children you had, even though it probably did, that was 13,854 dads with one kid, living in RVs.

The last category was hardest. Dad would have Dorothy’s scalp if she so much as thought of him as a “conspiracy theorist.” And he isn’t, really. But Dad’s quest was a necessary part of the equation. The best she could manage was how many people believed in Bigfoot (13.5%). Dad doesn’t, but Dorothy has to make do. That brings her total number to 1,870.29.

One thousand eight hundred and seventy kids. Upon starting the exercise, Dorothy assumed the answer would be something like twenty. She could make paper dolls of them. A severed arm, maybe, for the .3 left over.

Making one paper doll a day, Dorothy could make 1,870 in barely more than five years. She might have met one of those kids by then. She wishes she could calculate the probability of that, as she watches the city of Chicago fall away outside the RV’s window and become the fields of corn that will flow right on into Kansas, but it’s beyond her.

Dorothy wonders if it’s even possible to calculate the odds of finding the Viper-King on this journey. What sort of numbers would she need? How many people send prank emails? How often “evidence” of mythical monsters is debunked? The size of the snake? How much of the world has gone unmapped, uncharted, long enough for something massive, omniscient, and strange to lie hidden there? The odds of finding such a thing, if it has not already been found, seem infinitesimal. Vanishing.

Who wrote about the Viper-King in the first place, anyway? And how did he know about the fat? Did he take moments out of his omniscience to record the legend for others? Was there more than one of these creatures? Did they breed? Or was it really like kingship, a mantle passed down, that no one got rightly until the previous owner was dead? Did a regular viper occasionally get a hell of a shock?