“Nice little city you got here,” a character in Jule Selbo’s red-blooded debut mystery, “10 Days,” says at one point to Officer Dee Rommel, and Dee couldn’t agree more. In fact, there may be some protectiveness of her hometown’s honor mixed in with the sense of professional obligation that compels her to return to the job that cost her a leg the previous year.

One June morning, a man shows up at the Portland office of G&Z Investigations with a proposition for Dee — he says that her boss, Gordy Greer, has recommended her for the assignment. Dee, who is logging hours as a bookkeeper at G&Z while on medical leave from the Portland Police Department, isn’t looking to get back in the game. But she keeps an open mind following a phone chat with Gordy, who reveals that the potential client is multimillionaire tech entrepreneur Philip Claren and, more to the point, Gordy’s childhood friend.

Claren has been blindsided by the news that his 22-year-old daughter, Bunny, who heads a lab at Claren Tech, is marrying a man named Tyler Peppard. Claren knows nothing about Peppard – could he be after Bunny’s cash? – and would discuss this turn of events with Bunny himself, but he hasn’t been able to reach her in days. More worrisome still: Claren has just received a note that Bunny mailed in New York – she was there for a bio-engineering conference – that said, “Dad. Getting married. June 22. Bunny’s Point. Chebeague.” To Claren and Bunny, Chebeague isn’t just a group of islands. As Claren explains to Dee, he and Bunny made a pact: if she was ever in a tough spot, she was to send him their code word, Chebeague. After that, his job was to “move hell to get to her.” Which is where Dee comes in.

Dee feels she owes it to Gordy to accept the assignment, plus she could use the serious money that Claren is promising – for a new car, for her medical bills. And could it be that something Gordy tells her over the phone has some sway?: “You gotta say ‘yes’ to life, Dee.” She takes the Claren case, knowing that the clock is ticking, and loudly: June 22 – Bunny’s wedding day – is only 10 days off.

There’s even less time to devote to the Claren case after Dee learns the next day that her friend Karla hasn’t shown up for work at her salon and can’t be located. Dee has her suspicions: just the night before, she sat at a booth at Sparrows watching Karla get into a pickup truck with her recently sprung former-jailbird ex. It was also at Sparrows that Dee met Thomas Charles Beene, the liquor salesman whose body has just been discovered floating off Widgery Wharf. Dee now finds herself triply consumed by questions: Where’s Bunny? Where’s Karla? And what happened to Beene? It’s enough to divert her from another pressing matter: her chief has given her until the end of the month to decide whether she’ll return to the force.

From her website, it’s apparent that Selbo, who now lives in Portland, has had an impressive career in film and television, and “10 Days” does indeed have something of a cinematic shimmer about it. The novel offers an acute sense of place – a guidebook’s worth of Portland touchstones cameo or get name-checked in “10 Days,” including J’s Oyster, Standard Baking Co. and the fine newspaper you’re reading now. And the book features a quirky and presumably cinegenic assortment of Mainers that Dee taps for help, among them a former Homeland Security employee turned stay-at-home Kennebunkport mom and a Somali University of Southern Maine student who has pursued a sideline at G&Z fully expecting to see American justice in action.

“10 Days” could have used a bit of tightening, and it’s the kind of thriller in which people sometimes behave in ways that aren’t plausible so much as necessary to move the plot along. But there’s reliable pleasure to be found in narrator Dee’s prickly volleys with foes and friends alike, and her reckoning with her new disability is handled with both candor and acuity.

“10 Days” is the first Dee Rommel title in a projected series, and readers familiar with J.-K.-Rowling-as-Robert-Galbraith’s mysteries revolving around private detective Cormoran Strike, who lost a leg in Afghanistan, may fantasize that Selbo can work her entertainment-industry connections and engineer a crossover vehicle for the two bloodied but unbowed sleuths. And after they finished their crime fighting, they could take in a Sea Dogs game.

Nell Beram is a former Atlantic staff editor and coauthor of “Yoko Ono: Collector of Skies.” Her work has appeared recently in The Cut, The New Yorker, Salon, and Shelf Awareness.