The Swordsman of Mars

Harry Thorne had lost everything: his business, the love of his life, even his own self-respect. As he's contemplating suicide he's made an incredible offer. He can go back in time and switch places with a look alike who lived on Mars millions of years ago when it was a lush, beautiful planet full of promise and adventure. Seizes his last chance at salvaging his life is transported millions of years into the past to a Mars peopled with beautiful women, mighty warriors, fearsome beasts, and awesome magics.