Retrograde: A Post Apocalyptic Thriller

"Clayton Shepard dropped from the sky. Twice. Now, in the wake of twin cataclysmic blasts of energy from the sun, he is earthbound and far from home. While his family and friends seek safe harbor in an increasingly dangerous Texas, Clayton is forced underground in Colorado. He must free himself and finally find a way home in a world quickly slipping farther into the dark ages." — quoted from this book's product page on Amazon as of 2018-06-12.