JONATHAN LETHEM'S last book was about an alternate-universe New York City that featured bizarre weather patterns, a rampaging tiger, and an astronaut slowly dying in space. Symbols were involved—lots and lots of symbols. His newest, Dissident Gardens, is a clear-eyed and welcome return to reality: It's an ambitious treatise of a novel, a survey of radical leftist American political movements hung on the backs of a handful of vivid, compelling characters.

At the pulsating center of Dissident Gardens sits Rose, a fierce Jewish Communist who moved to Queens in the 1930s. As the book opens, in 1955, Rose is being exiled from the Communist Party—for, we're told, fucking a black cop. If she seems something of a hero in the early pages, resistant to the petty prejudices of her party, it's soon clear that living by her beliefs hasn't done much for Rose's personal life: She's alienated her daughter, driven away her husband, and made enemies of the neighbors in the leftist enclave where she lives.

From Rose, Lethem's chapters tentacle outward to encompass the lives of a wayward hippie daughter, a gay black intellectual, a pervy cousin, a sad grandkid, and a couple of ineffectual protest singers. Oh, and someone has an Abe Lincoln fetish—but I'm not telling who.

From communism in the 1930s to communes in the 1970s to the ragtag Occupy protests of a few years ago, Dissident Gardens is a scrapbook of scenes and eras from New York's radical left, all told through people whose lives Rose affected. (Usually for the worse. Nobody really likes Rose.)

Dissident Gardens clocks in at just under 400 pages, but it feels much longer: Lethem's sentences are dense knots of history and philosophy, as well as Lethem's reliably nerdy attention to niche interests, ranging from coin collecting and baseball to the best gay hookup locations in New York in the early '80s. (During "the unashamed homosexual bacchanal that had become possible in the historical margin between Stonewall and disease.") The prose is by turns thorny and colloquial, funny and bawdy, and intellectual. It's a slow read, but a rewarding one.

But for all that, the book feels long. It also doesn't feel long enough: The political overshadows the personal, and we're left with what feels like frustratingly little about each of the characters.

As Lethem's characters converge on the present moment, the politics of Occupy waft across the final pages, courtesy of white kids in dreadlocks whose ideas, we're assured, are "viral." If it's a watering down or an adaptative evolution, well, that's up to the reader to decide.