At just a hair more than 200 pages, “A Guardian and a Thief” manages superbly (and efficiently) to be many things: A beguilingly simple tale. A complicated morality play. A sensitive evocation of a time — the near future — and a place — Kolkata, India — during a period of flooding, drastic food shortages and heat like “a hand clamped upon the mouth.”

Most universally, it is a story of human imperfection, of bad acts done for virtuous motives. And it all arrives naturally in an eventful narrative marked by accumulation and loss. Majumdar’s brilliant choices result in what feels like the ideal order. Instead of feeling jerked around by plot, we are borne aloft by story.

Lots of novels twice as long have half as much heft.

There are four main characters: Ma, her daughter, Mishti, 2, and her elderly widowed father, Dadu, are preparing to leave India, and join Ma’s scientist husband in Ann Arbor, Mich. Boomba, a destitute villager who moves to the teeming city in desperate search of opportunity, robs Ma’s house one night.

Ma has a master’s degree and a good job managing a busy urban shelter, from which she pilfers donated food. She justifies her thievery as a means of providing for her daughter and her family’s emigration. At the same time, she is not too proud, in an unforgettable scene, to dig through a mountain of garbage, “a mean-eyed bird” in search of “divine documents” (missing passports).

In Ma, Majumdar creates the novel’s richest human, someone worthy of cheers and jeers: at once a fierce mega-mom and a petty criminal, practical-minded and often oblivious to her own collapsed ethics, indignant when she feels mistreated, defensive about her own lying and thievery.

The ceaseless urge to trade one’s native country for a supposedly better life elsewhere — today’s politically hottest potato — is gorgeously humanized. Dadu would rather stay in his beloved city full of laughter and “street corner philosophers” than live abroad where ”he would be a diminished version of himself.”

For Ma, emigration from famine-threatened India to America — “a country of grocery stores as large as airplane hangars, stocked with waxed fruit and misted vegetables” — is an alluring lifeline and her duty as Mishti’s protector.