In the Old American West, Whitefeather is a half-Indian/half-French shaman with tormenting visions of an apocalyptic future where mankind has doomed itself after turning away from the law. He then has a further vision of mankinds salvation. He sees Arthur, the man who is destined to bring law to the world and the weapon that will bring about this change. A mystically-emblazoned gun, that can only be fired by one man, that will never miss and when aimed will bring down the heavens, firing thunder itself from its barrel. He sets out to find the legendary Caliber. An epic Western adventure like no other!