In the 3070s the world is certainly a much different place. Centuries before a global natural disaster had reduced the population to nearly 10% of its former number. This led to two-thirds of the United States being left uninhabited.

In this setting main character Dan Kelley, a young history professor, unintentionally discovers prehistoric cave symbols carved into the back of a uniquely crafted paving stone. The stone was created by a mysterious mason who years earlier buried similar stones mapping a peculiar course across the unpopulated prairie. Following these clues Dan was able to retrace his parents path and uncover details of their disappearance, which had left him orphaned at age four.

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