Endworld: Denver Run: Endworld Series, Book 8

The last vestige of civilization was under attack by a horde of savage fighters, determined to plunge the world into total darkness and ignorance. Undermanned, outgunned and overmatched, the Warriors of the Home desperately need help. But help was hundreds of miles away in Denver, and only one man had the courage and strength to accomplish the impossible. If he failed, the Home would perish; if he succeeded, it might be his last act of heroism.