I thought I understood pseudonyms.

They are what you use when you publish something but you don’t want people to know you wrote it. I can think of some legitimate reasons to use them. I have used them in the past. But I won’t tell you what they were, because that defeats the purpose of using pseudonyms.

But if you go to John Sandford’s website and you click on the “author” tab, in the very first sentence you learn that “John Sandford is the pseudonym of John Roswell Camp, an American author and journalist.

Camp won the Pulitzer Prize in journalism in 1986 and was one of four finalists for the prize in 1980. He also was the winner of the Distinguished Writing Award of the American Society of Newspaper Editors for 1985.”

Apparently, Camp adopted the pseudonym “John Sandford” in the late ’80s. According to his author’s page: “When it became apparent that his first two novels, ‘Rules of Prey’ and ‘The Fool’s Run,’ were going to be published only three months apart, by different publishers, G.P. Putnam’s Sons asked him to come up with a pseudonym for ‘Rules of Prey.’ The publisher felt the near-simultaneous release of two different books, written in different styles, could create a marketing problem. Camp is a Civil War buff, and chose the name Sandford after his paternal great-grandfather, Henry Sandford, who fought with the Belle City Rifles, part of the Union Army’s Iron Brigade, in that war.”

OK, I guess marketing people know what they’re doing and didn’t want Camp/Sandford competing against himself. When the books came out, “Rules of Prey” by John Sandford — the very first in what would turn out to be the long-running Lucas Davenport series of which his latest book, “Toxic Prey” is the 34th — was more popular than John Camp’s “The Fool’s Run,” so Camp and his publisher decided to go with Sandford.

Which, I guess makes a little bit of sense. Maybe it’s analogous to a business person establishing a corporation to shield themselves for personal liability. You draw a bright line between your work and your life. Actors use stage names, singers adopt performing personas; maybe there is some psychological benefit to insulating yourself this way. Lots of authors, from Eric Blair to Stephen King, have used pen names for various reasons. “Lee Child” is also

a transparent pseudonym.

But it has some disadvantages as well. For one thing, most writers actually like being known for their writing. Maybe that’s the main reason Irish novelist John Banville decided to ditch the “Benjamin Black” persona he adopted for his detective novels

Some assume “John Sandford” isn’t really so much a pseudonym for John Camp as a brand name stamped on books ghostwritten by dozens of writers — that it’s an imprimatur like “James Patterson,” a real person who started out as a writer but seems to have evolved into a kind of creative director who collaborates with other writers on thrillers that are published under his name. I’ve actually read that the John Sandford books are produced by “various authors.” How else to explain the 58 books — mostly novels published under the Sandford brand since 1989? Surely they must be some sort of fiction-churning factor staffed by offshore novelists?

I don’t think — I have no reason to believe — this is true.

Now Patterson has been very open about his process; he has said he is more comfortable dreaming up thrilling plots than setting down words in sentences. He lets others handle the details, like an Old Master assigning a journeyman to paint the background. This is fine. I’ve not read any of Patterson’s books since that 2018 debacle he did with aspiring author Bill Clinton, “The President Is Missing,” but I don’t find his methods scandalous. Lots of people — probably most people — are more concerned with making money than creating art, and no one (aside from book critics whose editors strongly suggest they review books like

“The President Is Missing”) is forced to read anything “James Patterson” writes.

But a John Sandford book is a lot better than most James Patterson books. I’m a fan of John Sandford.

And I don’t think we should discount the idea that some people can do extraordinary things. I just accept that John Camp — who has written a couple of nonfiction books under his birth name — writes a lot of books as John Sandford. And I like most of them.

On the other hand, you don’t write 58 full-size novels in 35 years without arriving on some efficiencies. At this point, I don’t imagine it is hard for Sandford to write a suspense thriller featuring one of his main protagonists like Lucas Davenport or Virgil Flowers; all he has to do is set up a scenario where the bad guys are threatening to blow a hole in the world (or, as in the present book, worse) and set his characters down and watch them solve the problem. At this point, most of the work is done before the book even starts — Sandford has done such a good job of defining these characters, assigning them specific traits and tastes and foibles, that the actual narratives can be handled with simple stage directions and dialogue. We don’t need any internal monologue-ing, because we know what kind of people Sandford’s cops are — no-nonsense, humane and empathetic but perfectly willing to put a bullet in your head if that’s what the algorithm requires.

A LONG HISTORY

Even if you’ve never read Sandford before, you’re likely to sense that these characters have plenty of ballast and backstory, a long history together. Hemingway believed that if you knew a lot about a character, you didn’t have to tell the reader everything, or even a lot about that character, you just had to keep the character true to their own circumstances and experience. Sandford might blush at the comparison to Hemingway — certainly Sandford’s plots are more overt and fantastic; maybe he isn’t as interested in the psychological consequences for his characters or in the freightedness of plain language — but one could argue that Hemingway’s books work in the same way as Sandford’s, at least in a technical sense.

The main difference is Sandford is unabashedly producing entertainment product, not literary fiction, and God bless him for that. (Though if he ever writes an advertureless novel about the daily routine of a 14th-century cloistered nun under his own name I might re-think my position.) He’s giving us quality hero cop pulp and cashing a lot of checks. And why not? He already has a Pulitzer Prize.

And he’s one of those thoroughly clean writers who never seems to hit a sour note; what I think of as a “Teflon bullet” writer. Sandford’s prose is deceptively simple, considered and intelligent. This is what some people mean when they say a writer is a joy to read — his sentences are never thorny, you never snag on them.

This book features U.S. Marshal Lucas and his grown-up adopted daughter Letty (now an investigative agent with Homeland Security) as they try to track down a British scientist, Lionel Scott, an expert in tropical and infectious diseases, who means to kill 80% of the humans on Earth in an effort to arrest global warming and save “Gaia,” the name he and other radical environmentalists use for the living spirit of the planet. (The mythical Gaia was the primal Greek goddess personifying the Earth — the Greek version of “Mother Nature.”)

In order to do this, Scott has recruited a few true believers and brewed up a hybrid bug with the killing power of the Marburg virus and the transmissibility of measles. Scott and his Gaia cult mean to infect themselves with the virus (after availing themselves of the vaccine Scott has created) then open and spread vials of the stuff around the world’s major airports.

After Scott disappears in the United States, Letty is sent to the U.K. to gather intelligence on the missing scientist; there she “liases” with handsome and frisky MI-5 agent Alec Hawkins, who is drawn into the core investigative unit along with Lucas’s U.S. Marshal Rae Givens (the name is a not-so-subtle nod to Elmore Leonard’s character Raylan Givens).

Soon their search for Scott and his accomplices centers on Taos, N.M., and a lot of theoretically disturbing moral choices have to be made, as the implications of a — reasonable, given the circumstances — “shoot on sight” order play out. While the eco-warriors do mean to murder millions, their motives are not “evil,” but rooted in the desire to save the human species along with the Earth herself. And so this particular John Sandford book takes on a slightly more somber tone than most of the others. Usually these kind of books are high-contrast — “Toxic Prey” has a least a touch of gray.

A TIME PASSER

But the real truth is the story isn’t going to stick with me, though it will become another data point in the Lucas-Letty-Virgil universe (Virgil, the Lucinda Williams fan who often provides Sandford’s books with genuinely funny moments, is missing from this novel). The book just serves as a way to pass a few hours.

What’s remarkable and deeply interesting is Sandford builds these remarkably intricate machines designed to transport us from our everydayness to this heightened, bold and cinematic world. Each one is built to close tolerances, and, like a well-made revolver, is heavier than it looks. But no two are quite the same.

And that may be what makes them art.