It is the future. Due to worsening conditions on earth, largely because of overconsumption and global warming, a consortium of nations has established a colony on Mars, now in its fourth year. Our hero, a teenager named Cornelius with many special supernatural powers, flies on Mars to live with his great-uncle and to intern with a team of archaeologists hoping to discover prior life on the red planet. He meets a girl on the space shuttle ride, and together they begin internships with an intrepid team of scientists.
To pass the tedious hours of collecting data, Cornelius entertains his love interest by telling her the history of his family from approximately the year 1 to today. While he frames these stories as a series of heroic escapades about which he is unusually knowledgeable, Cornelius is actually a supernatural time traveling being. He is reincarnated again and again through time, and his purpose in each incarnation is to find his family and use his special abilities (which include ESP, the ability to see the future, and superior leadership skills) to help them out of whatever trouble they might be in. These troubles vary from the Protestant Reformation to the French & Indian War to global warming.
After chapters and chapters of this sort of reminiscing, the plot in the present (future) thickens as the colony receives word that the nations on earth no longer have the resources to fund it, and want them all to return home. Meanwhile, Cornelius is slowly discovering that various people (including his great-uncle and the head scientist on the expedition) are also time travelers and have in fact known him in previous lives. Together, using their common powers of premonition, they determine that the colony must not return to earth. Why? The giant volcano under Yellowstone National Park is about to erupt, killing everyone on earth and rendering the planet uninhabitable for at least eight years. Instead, they must learn to survive independently and sustainably on Mars, all alone. Or so they think. An exploratory expedition leads to an encounter with Martians, who have been living quietly on Mars for millennia. The two groups must learn to cooperate. They do, and together soon build a thriving multi-cultural society on Mars. At the same time, all life on earth is destroyed by the volcanic eruption.
END OF BOOK 1
There are also plans for a sequel, in which Cornelius and his love interest return to earth and successfully repopulate the planet.