Ultimate Comics Captain America (Ultimate Comics Captain America #1-4)

Captain America has finally met his match: Captain America. Frank Simpson is a man without a country. The secret Captain America of the Vietnam War, he was augmented and experimented on by the military, to soldier on while the original Cap was missing. But Simpson became disillusioned with America and deserted in 1972. Now he's back, with an entire army of Super-Soldiers at his disposal. His mission: to break the original Captain America and, in his words, make him 'see the light.' Can an icon be destroyed? Or is Steve Rogers truly unbreakable? Captain America faces his greatest challenge, learning more about both himself and his country than he ever bargained for!

Collecting ULTIMATE COMICS CAPTAIN AMERICA (2011) #1-4.