I’m not in the business of giving advice, but the following wisdom I dispense confidently: Do not go running while trying to listen to Thomas Pynchon’s “Mason & Dixon” on a cassette player. It’s frustration guaranteed, especially after the belt clip on your Walkman breaks off and you’re forced to carry the ungainly device in your hand. You have the next tape in the 20-cassette set rattling in a shorts pocket; in your other pocket is an iPhone, because obviously your Sony Walkman WM-FX303 is not connected to the internet, and you should probably be connected to the internet, lest during your bout of fitness the United States launches a war against Iceland or you’re commanded to stop at Whole Foods for milk.

So there you are, trying to keep your pace below 17 minutes per mile, while the narrator, Jonathan Reese, reads from Pynchon’s saga about the “savage Vacancy” called America.

“Mason & Dixon” was published 20 years ago this spring, but I first read it during the George W. Bush years. Those were the days of liberal anger and paranoia, undisclosed locations and known unknowns, tyrants pulled out of spider holes and America pulled into imperial adventures. You couldn’t do better than the most recent work by our poet laureate of the deep state, the postmodern Virgil whose novels, wherever and whenever they were set, always led into the darkest byways of the military-industrial complex.

Here was a 773-page historical hallucination written in the madcap 18th-century English of Henry Fielding, nominally about the two surveyors who charted the dividing line between North and South, though really about the anxieties that have always animated Pynchon: the violence at the heart of the American project, the recursivity of history, paranoia as both survival strategy and dangerous narcotic, so that even a seemingly straightforward assignment becomes, as Charles Mason and Jeremiah Dixon come to realize, “a conduit for Evil.”