"The Revisionists" by Thomas Mullen, Mulholland Books/Little, Brown, 448 pages, $25.99

Atlanta-area novelist Thomas Mullen possesses an expansive imagination. Many novelists, including some of the best, render the world as it is. Mullen renders the world as it is not and probably never could be -- yet manages to persuade readers to suspend disbelief and become engaged in the story.

“The Revisionists” is Mullen’s third published novel. The previous two -- “The Last Town on Earth” and “The Many Deaths of the Firefly Brothers” -- can be fairly categorized as historical fiction. But “The Revisionists” bends the element of time in ways so strange that it is impossible to describe whether it is historical, futuristic, present day, none of those or all three.

Somehow, Mullen builds a novel around the science-fiction conceit of time travel while producing a book that cannot simply be categorized as science fiction.

A warning of how Mullen plans to bend time can be found in a quotation at the beginning of the book from Norman Mailer, writing about himself in the third person: “Mailer was haunted by the nightmare that the evils of the present not only exploited the present, but consumed the past, and gave every promise of demolishing whole territories of the future.”

In the book, a character named Zed lives in a future time, somewhere other than planet Earth. He is sent to Earth on a mission by his government, using the name of Troy Jones, who on Earth is a disappeared employee of the top-secret National Security Agency.

Zed’s job is to “protect the Events,” to ensure that Earthling history circa 2011 is not altered by the enemies of his government, called Hags, an abbreviation of "historical agitators.”

The Hags, you see, journey to Earth from the future hoping to alter history so that hatred does not lead to so many deaths. For instance, the Hags will insert themselves into Earthling history so the U.S. government refrains from dropping nuclear bombs on Japan near the end of World War II.

It’s not that Zed glories in mass destruction. He sees his job clinically, protecting the integrity of history as writ on Earth -- in his own words, ensuring “that awful events unfolded as originally dictated by history, that the Hags did not rewrite the final acts of tragedies to make them comedies.”

That may sound like an unlikely concept for a successful novel, yet Mullen makes it work, alternating among four chief characters: Zed; Tasha, a Washington lawyer representing evil corporations who is beginning to question the morality of her work, especially in light of her brother’s mysterious death while serving in the U.S. military; Leo, a former spy for the Central Intelligence Agency who is rootless in Washington after being fired for questioning authority too blatantly; and Sari, a 22-year-old Indonesian woman employed by a family of Korean diplomats posted to Washington who treat her as an indentured servant.

The paths of Zed, Tasha, Leo and Sari cross in unexpected but credible ways. As their lives become increasingly intertwined, danger lurks around every corner. (The cliché is appropriate. Despite Mullen’s skill as a novelist, the plot and the language feel clichéd from time to time. The novel is superb, but not perfect.)

In the opening chapters, Zed tries to avoid caring about Tasha, Leo and Sari, assuming based on his knowledge gathered in the future that they will soon die in an event known as the Great Conflagration.

But as the novel progresses and Zed begins to question his mission, he might hold the ability to prevent the Great Conflagration by refusing to combat what the Hags are hoping to accomplish. Readers will not know until the end of the story whether Tasha, Leo and Sari die in a massive disaster or might survive to the end of a normal life span.

Mullen is a skilled storyteller. The novel, however, is much more than a page-turning techno-thriller. It also serves as a vehicle for philosophical musings.

Some readers might find the musings shallow; others might see them as profound. It is probably correct to think of the novel as an anti-war tract, an indictment of avoidable human folly leading to wars year after year, decade after decade, century after century.

Steve Weinberg is a member of the National Book Critics Circle.