Imagine a search for identity on an epic scale, and you’ll have some idea what the novel “Pym” is about. It tells the story of Chris Jaynes  – a professor who becomes obsessed with finding a mythical black homeland referenced by Edgar Allen Poe in his only full-length novel, “The Narrative of Arthur Gordon Pym of Nantucket.” But “Pym” is more than a novel; it’s a biting satire of how Americans see race, and see themselves, in the 21st century. We talk with author Mat Johnson about his book and his personal journey exploring race as a biracial American.