I mean no disrespect, and I count myself in their number, but I'm wagering that most Americans have a half-baked understanding of the Indian caste system. It is complicated. Unless we are students of the Indian subcontinent, we simplify caste into a gradation of wealth and power, which slowly diminishes until we arrive at those who have little of either, unforgettably referred to as untouchables. Could this system still exist is this modern age? Why, yes, it could, and it does.

By the time you finish reading Sujatha Gidla's "Ants Among Elephants" — and again I'll offer a wager: If you start her book, you will finish her book — your appreciation of the Indian caste system will have become finely tuned. Via the march of history and dint of circumstance, and for a good time now, the Hindus have brokered power and wealth in India, formalizing and institutionalizing the caste system, a subatomic delineation of entitlement and bigotry, in operation everywhere and all the time.

To the manor born, then, or the hovel. Gidla drew the short straw. "I was born in south India, in a town called Khazipet in the state of Andhra Pradesh. I was born into a middle-class family. My parents were college lecturers. I was born an untouchable." By what contingency? Her family was Christian. "Christians, untouchables — it came to the same thing. All Christians in India were untouchable … I knew no Christian who did not turn servile in the presence of a Hindu. I knew no Hindu who did not look right through a Christian man. I accepted this. No questions asked."

Until Uncle Satyamurthy, her mother's older brother — a principal architect in the leftist, armed movement to overthrow the Indian government in the 1970s — hove into her view.

Gidla's writing starts out clipped and dark. Uncle Satyamurthy is the hub of her tale, but the bigger story is about her family — mother, father, uncles, aunts, grandparents — and their navigating the waters of late colonial and then early independent India. This is a real story, ringing true, told with wide-eyed wonder, and it invites you right into the family, to be a familiar, to understand.

At times, Gidla works in broad strokes; the stages upon which the chapters play out are fully set. Each chapter resembles a step in the making of the Indian bread puri: an assembly of the basic ingredients, kneading them together to create the general picture, pulling pieces from the dough and rounding them into distinct characters, squashing them flat as if by the hand of experience, then transformed by heat into something unrecognizable: bread lighter than air, a self-possessed untouchable. Revolutionary.

“Ants Among Elephants,” by Sujatha Gidla

There is also a fine-grained history of the subcontinent taking shape in the book as Gidla gathers her family's, and in particular her uncle's, story. Satyamurthy is a rich character. He can be a dreadful prig, but on the other hand he knows how to laugh, how to take the rough with the smooth. He leads a fascinating life, and the highs and lows of it make for a good investigation into the roil of post-independence. Satyamurthy is true to himself — he is a revolutionary fighting iniquity, a poet and once, to make ends meet, a professional writer of love letters — and doomed.

Whether you buy into his Maoism — which is not the full-blown, Little Red Book-waving variety, but the "Political power grows out of the barrel of a gun" stripe — that brand of guerrilla warfare continues to be in motion today via the People's Liberation Guerrilla Army.

Gidla is our Virgil into the world of the untouchables and their acts of defiance; not just as an observer, but as a participant. She is bitten by the revolutionary bug, and bitten hard: arrested by the Indian authorities, tortured, left to rot, released. She has been party to the heights and the depths of living a revolution. Today she resides in New York City, and after a period of working in software applications, she decided to become a train conductor in the city subway system, the first Indian woman to so serve. Still a revolutionary.

Peter Lewis is the book review editor at the Geographical Review.

Ants Among Elephants
By: Sujatha Gidla.
Publisher: Farrar, Straus & Giroux, 306 pages, $28.