“The Last Thing He Told Me” is a mystery about a missing man, and yet it’s a show that wants to be about how to mom.

Those two narrative impulses are organically entwined throughout this new Apple TV+ limited series, yet they often work at cross-purposes. The puzzle-solving’s momentum demands too much of the stepmother and daughter’s attention to allow them to really burrow into the particulars of their growing bond. And when the crime story takes phony or trite turns, falling back on emotion doesn’t always rectify the problem.

Sometimes, however, the threads mesh. Whether you buy the story or not, it has some decent things to say about love, family and forgiveness. Despite being sluggishly paced at times, the narrative’s twin engines generate interest nearly all of the way through the show’s seven episodes.

It’s one of Reese Witherspoon’s Hello Sunshine productions, so there’s a minimum standard of intelligence and craftsmanship, too.

That won’t add up to a satisfying whole for everyone, but fans of Laura Dave’s bestselling source novel ought to be pleased. She adapted the book with her husband Josh Singer, the distinguished screenwriter of “Spotlight,” “The Post” and “First Man.”

Jennifer Garner looks constantly concerned as Hannah Hall, a woodturner (lathe sculptor) who was raised by her grandfather and hadn’t gotten around to establishing a family until she met Owen Michaels (Nikolaj Coster-Waldau of “Game of Thrones” fame). He’s the sweetest guy and a widowed software coder who dotes on his 16-year-old daughter Bailey (impressive young Australian actress Angourie Rice of “Mare of Easttown”), who is an enthusiastic theater kid, has a nice boyfriend and is otherwise surly.

Bailey doesn’t so much hate her new stepmother as just doesn’t see any need for her (“extra” is her favorite word for Hannah). She’s been so close to her dad since her barely remembered mother was killed in a car accident that Bailey just plain resents another adult presence in their Sausalito houseboat, despite it being roomy enough to have a walk-in closet.

Owen assures Hannah the Bailey situation is no big deal, and their lives are otherwise blissful. Until the day she’s delivered a terse note from her husband: “Protect Her.”

The FBI has raided the company he works at — some Enron-style skulduggery, we’re informed, which could be interesting but the show lets that investigation slide — and Owen is nowhere to be found, though he did manage to leave a duffel bag with $500,000 in Bailey’s school locker. Days of stress and side-eyes ensue, while shady strangers show up on their dock. One of them, Grady Bradford (Augusto Aguilera), claims to be a U.S. marshal and tells Hannah, “Owen Michaels is not who you think he is.” So Hannah and Bailey decide to track down some vague clues about Owen’s past in Austin, Texas.

Luckily, Hannah maintains a supportive personal research team in the Bay Area that consists of best friend Jules (San Francisco nativeAisha Tyler),a Chronicle reporter who helps to a professionally questionable extent; ex-fiance Jake (Geoff Stultz), a lawyer who still cares for Hannah and knows a top private investigator; and maybe even that Grady guy, who follows the women to the Lone Star State.

The pair’s shoe-leather work in Austin — from the Longhorns’ DKR Stadium to other sites on the University of Texas campus, area churches and one rather significant bar — reveals as much about who Bailey might really be as what happened to her father. It’s a poignant journey for the girl and brings her closer to Hannah, who gradually finds her inner mama lion.

Though a heart-on-her-sleeve type, Hannah discovers a terrific capacity for lying to get the clues she wants. Garner clearly enjoys playing these scenes, and it’s fun to watch because it’s such a break from seeing her acting worried most of the time.

与此同时,原来还有另一个组of criminal predicaments in Texas. They’re the type we’ve seen numerous times before, and even the welcome humanism with which “The Last Thing He Told Me” handles crooked cliches can’t freshen them up much.

Still, who’s going to argue with maternal instincts coming out swinging? Certainly not this show.

Bob Strauss is a freelance writer.