It’s Halloween 2001, just weeks after the events of 9/11. In a leafy suburb west of Boston, kids are out in costume, trick-or-treating. Among them is a pair of Middle Eastern brothers dressed in provocative garb: The older, about 16, wears a white robe and headdress, revealing only his eyes and brows. In one hand, he’s holding a metal dog leash. Attached to the chain, his younger brother sports a U.S. Marine camouflage uniform, splattered with apparent blood. Red paint drips from his eyes.

Going door-to-door, the trick-or-treaters introduce themselves as “a terrorist,” the older one says, tugging on the leash, “and a dead American,” proclaims the younger.

So begins the novel, “Girl Held in Home,” a noir tale that harnesses the folly of our post-9/11 world. Author Elizabeth Searle, who teaches fiction at the University of Southern Maine’s Stonecoast MFA program, has penned a domestic thriller that’s nearly self-propelling. The pervasive jitteriness that followed in the wake of 9/11 yields a cast of characters that’s chronically on edge.

Maura Simon is a Volvo-driving, liberal-leaning mom who co-chairs the 9/11 fundraiser at her son’s private school. Her husband, Dan, is a workaholic, forever stuck in airports and train stations due to bomb threats. Their testosterone-fueled son, Joezy, 15, has become fixated on the new Middle Eastern family in town, the Jiluwis, whom he dubs “our neighborhood’s Terrorist Cell.” Their nearby house appears to be a hotbed of strange goings-on.

In the matter of the Jiluwis, a swirl of rumor and speculation has taken hold. Beyond the Halloween antics of sons Rakeen and Rasha, there’s the family’s supposed royal lineage — their father is a Saudi prince. Every few days, fresh Arabic graffiti turns up on their garage door, visible to everyone, but understandable to few. At night, piles of boxes labeled “insulin” arrive by truck, delivered to their garage. And they’re harboring a Vietnamese girl, Le Ti One — “One,” for short — who may be an unpaid servant and hostage, in need of rescue. That, at least, is Joezy’s fervent hope.

While the plot suffers from a few too many convolutions, Searle makes hay with the paranoia that has spread in the age of 9/11, as well as its repercussions. When Maura and Joezy spot the Jiluwis in the supermarket, a series of reactions unfold.

“One tight-lipped older woman steered her cart of grain-free cat food pointedly away, out of their path,” Searle writes. “A mustached man plainly glowered as he tracked the pair. He stood before the white asparagus folding his muscular arms as if defending America itself.”

At the other end of the spectrum, Maura exudes the guilty self-awareness of a security mom who nonetheless preaches tolerance: “‘I’m sorry,’ I found myself wanting to bleat as (Rakeen) passed. ‘Sorry about the FBI agent in the sedan, watching your house. Sorry about all us skittish middle-class Whole Foods shoppers, watching you now.”‘

Throughout the book, people are constantly watching each other, catching one another in various acts that may not be what they seem. Indeed much of the book hinges on sorting out appearance from reality, and exposing a chasm of cross-cultural miscues. Nowhere is this more apparent than with the vague and shadowy One, the hostage-servant whose English is, at best, notional, rendering her circumstances opaque to outsiders. Still, Joezy remains smitten and hopeful to the end.

In this serio-comic novel, Searle has managed to take such meaty topics as bigotry, fear, and hysteria, and whip them into a tasty stew. By alternating between dual narrators — the manic Joezy and the fretful, reasonable Maura — Searle balances the moral and emotional sides of these issues, while serving up more than a dollop of satire.

Yet if Searle’s fiction seems over-the-top, consider this fact: The back-story about a girl held captive as a servant, and the brothers’ Halloween prank, derives from real life. A similar scenario took place near the author’s suburban Boston home.

Joan Silverman writes op-eds, essays, and book reviews for numerous publications.