In 2006, Sara Shepard published the best-selling novel “Pretty Little Liars,” the first in what would become one of the most successful young-adult suspense series ever. Eventually stretching out to 16 novels, the “Pretty Little Liars” juggernaut followed the misadventures of four teenage wannabes who cope with blackmail threats and worse after their Queen Bee mysteriously vanishes. Think Bess and George suddenly adrift without Nancy Drew’s confident stewardship and you have something of the central premise — if not the naughty behavior and menacing atmosphere — that fuels this series. “Pretty Little Liars” the novel begot “Pretty Little Liars” the television series, which ran for seven seasons beginning in 2010. (A spinoff, “Pretty Little Liars: The Perfectionists,” looms.)

“The Elizas,” by Sara Shepard (Atria)

All this is to say that Shepard is one of those sublimely successful authors whose books sell themselves. Her swarm of fans who have come of age with “Pretty Little Liars” — and Shepard’s many other YA novels — will not be dissuaded from reading her new book, “The Elizas,” a thriller aimed at an adult audience, no matter what scorn I heap upon it.

But, though the effort be futile, heap I must.

Like “Pretty Little Liars,” “The Elizas” is grounded on a big contrivance: In this case, a soon-to-be-published debut novelist named Eliza Fontaine realizes that the murder attempts and various other torments she has inflicted on her fictional heroine are starting to happen to her. Is Eliza herself responsible for this real-life mayhem? (After all, she has a complicated medical history that includes a childhood brain tumor and consequent memory loss. Now a 20-something adult, she is prone to suicidal thoughts and behaviors, binge drinking, and blackouts.)

Or, perhaps Eliza’s canny publicist is wreaking this havoc. It’s true that Eliza’s near-drowning in a Palm Springs pool has been a boon for pre-publication orders of her novel! Or, maybe that odd guy named Desmond is to blame. He rescued Eliza from the bottom of the pool and now seems to be stalking her. Or, maybe the culprit is her drab and resentful stepsister Gabby, who works for a company that “makes scarves that cleverly hide headphones and neck braces and colostomy bags.” (It’s called That’s a Wrap.) Or, what about Eliza’s glamorous Aunt Eleanor, who abruptly disappeared years ago? Could it be possible that Aunt Eleanor (just like that vanished Queen Bee in “Pretty Little Liars”) might reappear and provide answers about the attacks, strange text messages and other tribulations now dogging Eliza? You betcha!

The author Sara Shepard. (Danielle Shields)

Interspersed within this story line are chapters from Eliza’s forthcoming novel, called “The Dots.” The plot of “The Dots,” which is every bit as mechanical as the main suspense narrative, focuses on a girl named Dot — who, like Eliza, had a brain tumor as a child — and her dazzling Aunt Dorothy, who seems to have a lot in common with Aunt Eleanor. “The Dots” opens on young Dot’s hospital stays. Long before Dot or her doctors wise up to what’s going on, we readers deduce that every time Aunt Dorothy appears at the hospital bearing some soothing tonic, young Dot gets sicker. It takes a very, very long time for the obvious diagnosis of Munchausen by proxy to be suggested.

Because of her memory problems, Eliza has no clue about whether the misadventures that she has conjured for Dot in her novel are fictional or true; nor does Eliza know for certain if she jumped into that Palm Springs pool or if someone pushed her; if the latter possibility turns out to be the case, Eliza may be forgetting essential details about her assailant’s identity that could now save her life.

Whatever. I wasn’t very far into “The Elizas” when I, too, welcomed the gift of forget­fulness. Shepard’s story line is simultaneously so ornate and empty that it dissolves soon after reading. ­Eccentric but flat characters populate the novel’s pages, and false alarms pop up in every ­chapter with humdrum predictability. Here’s an early example of one such melodramatic moment, which occurs when Eliza spots someone lurking outside her house:

“Something shifts in the shadows by my door, and I let out a yelp. A figure stands backlit in the sun, his features blotted out. I freeze. My fingers lose their elasticity, hardening to talons. The figure clears his throat and raises an assuring hand. “Eliza Fontaine? Desmond Wells.”

This is silly stuff, the kind of assembly line writing that gives thrillers a bad name. I’ve tried but failed to think of a single positive thing to say about “The Elizas,” but no matter. Word is the novel has already been optioned for a film adaptation.

Maureen Corrigan, who teaches literature at Georgetown University, is the book critic for the NPR program “Fresh Air.”

The elizas

By Sara Shepard

Atria. 339 pp. $26