“Mr. Untouchable” is a documentary about the rise and fall of Nicky Barnes, a young black kid from the streets of Harlem who went from being a teen-age heroin junkie to the most powerful black drug kingpin in New York City history. With first-hand testimony from Nicky Barnes himself, “Mr. Untouchable” goes deep inside the New York City heroin game of the 1970s. It is an epic story of business, excess, greed, and revenge.