Emily Blunt in Tate Taylor’s film of the best-selling novel. Illustration by Adrian Tomine

Here is an introduction to “The Girl on the Train.” Listen carefully, and answer the questions that follow. Rachel (Emily Blunt) used to be married to Tom (Justin Theroux), but Tom had an affair with Anna (Rebecca Ferguson), who is now his wife. He and Anna have a baby, whose nanny is named Megan (Haley Bennett). Megan looks a bit like Anna. She—Megan, not Anna—lives with Scott (Luke Evans), who is creepy and possessive, although Tom also looks a bit clenched. Not as clenched as Kamal (Edgar Ramírez), however, who is Megan’s superhot shrink. Rachel will later enroll as a patient of Kamal’s. Stay with me here. It so happens that Rachel, who is obsessed with her ex, takes a twice-daily train ride that passes the house where Tom and Anna live. One day, she—Rachel, not Anna—sees, or thinks she sees, a woman with blond hair, who could be Megan, although she might be mistaken for Anna, kissing a man with dark hair, who could be Scott, Tom, Kamal, or possibly the FedEx delivery guy, on a balcony. Faced with this devastating evidence, she, Rachel, becomes a sleuth, teaming up, slightly unwisely, with Scott, who believes, slightly wrongly, that she is a friend of Megan’s. So (1), who beds whom? (2) Who doesn’t? (3) Who gets whacked? (4) Why can’t Rachel mind her own business? (5) Frankly, who gives a damn?

Such are the issues that spring from the film, which is directed by Tate Taylor, written by Erin Cressida Wilson, and adapted from the novel by Paula Hawkins. Half the sentient beings on earth appear to have read the book, alleging with near-unanimity that they couldn’t put it down. I couldn’t pick it up. I tried, frequently, but it always fell from my grasp, tugged down by the dead weight of the prose. Still, plenty of viscous books have been transfigured into sprightly films. Clint Eastwood made something watchable out of “The Bridges of Madison County,” a public feat that ranks with the raising of Lazarus. Perhaps the same could be done with Hawkins’s narrators—three of them, no less, maundering on in the first person, often in the present tense, and each as annoying as the next.

Spirits rose when news of the cast arrived. Bennett is currently outgunning most of the guys in “The Magnificent Seven,” a flush of anger heightening the hue of her cheeks; Ferguson was top banana in last year’s “Mission: Impossible—Rogue Nation,” leaving a baffled Tom Cruise to work out what sort of banana he was meant to be; and Blunt is Blunt, a deserving object of worship ever since, armed with a queenly disdain and the best eyelids in the business, she held her own against Meryl Streep in “The Devil Wears Prada.” It is with infinite regret, therefore, that I must report on the veil of dourness that settles over all three actresses in “The Girl on the Train.” None of them are allowed a flurry of wit or a lighthearted shrug, and to switch from Grace Kelly, in “Rear Window”—a movie that dared to suggest how much fun might be had from the wicked watching of other lives and the amateur probing of crimes—to Taylor’s heroines is to pass from luminescence to a zone of querulous gloom. The tale is set largely in a suburb on the Hudson, and nothing is duller or more stifling, as a rule, than people who wish to make it perfectly plain how stifled they feel by their dull suburban existence.

Does it matter that the plot is so full of holes that you could use it to drain spaghetti? (For a more watertight version, consult Agatha Christie’s “4:50 from Paddington,” in which a passenger—a chum of Miss Marple’s, thank heaven—sitting in one train spots a strangling in another.) Newcomers, innocent of Hawkins’s novel, may not even care that the final twist is visible from many leagues distant. What does rile, though, is the drink. Rachel is a lush, decanting vodka tonics into a plastic beaker for boozing on the move, and Blunt presents a gaunt and sorry spectacle, with flaking lips, unfocussed gaze, and rosy nose. Whereupon she attends a single A.A. meeting and—bingo!—the problem starts to clear. We realize that alcoholism was never a serious theme; it was merely an excuse for false-memory syndrome, and hence a lazy way to mess with the logic of the story. Judging by the restive sighs that crowned the screening I went to, not everyone is fooled.

Last and least, there is the title. Whether there was an overt attempt, first by Hawkins and then by the filmmakers, to cash in on “Gone Girl,” I cannot say, but in both cases an enfeebling example has been set. By any measure, the principal figures in both works are women, and to label them as girls is to tint them with childishness, as if they were easily cowed by circumstance or stormy feelings, and thus more liable to lash out, or to sink into a sulk, rather than submit their troubles to adult consideration. In 1942, Katharine Hepburn starred in “Woman of the Year” as a prize-winning political columnist. Try zipping back in time, telling Hepburn to rename the movie “Girl of the Year,” and see how far you get.

A woman runs in terror down a street. Her feet are bare, and so is her head. She carries a child in her arms. Darkness has fallen, and it’s a relief when we see the lights of a police vehicle ahead; surely these men will come to her aid. Instead, they start to chide her, saying, “Are we in Europe now?”

No, we are not. Welcome to Tehran, in 1988, during the exhausted last stage of the Iran-Iraq War. Hundreds of thousands have died, and the city is a target for Iraqi missiles, but what concerns the authorities, at this instant, is that the woman has appeared outside without a chador. She is detained, and is lucky to get off with a reprimand. Her name is Shideh (Narges Rashidi), her child is Dorsa (Avin Manshadi), and they have just fled from their apartment. This is not because Shideh’s husband, a laughably handsome doctor named Iraj (Bobby Naderi), has been drafted to serve near the front line, leaving his wife and daughter to fend for themselves, or even because of the missile that landed, not long ago, on their building and failed to explode. (The nose cone protruded through the roof, and spidery cracks from the impact spread across the ceiling of the apartment.) What propels Shideh into the night is the belief, shared with her daughter, that their home is possessed by spirits.

“Under the Shadow” is being sold as a horror film, and understandably so; there are a few nasty surprises that will bop you right on the nose cone. At what point, though, will the unwarned viewer become aware that this is a horror film at all? Many scenes are chafed by vexations that could not be less supernatural: Shideh’s dismay upon learning that she is forbidden to complete her medical training; her quarrels with Iraj, who reckons that she should swallow that humbling fate; the solo workout sessions, in her living room, in front of banned Jane Fonda videos; her trips to the doctor, when Dorsa develops a fever; tea with the landlord’s wife; and the dashes to the cellar when the air-raid sirens cry. But there’s the rub. Low-grade horror rustles up its fears from nowhere, inventing cheap curses or doltish backstories, but the writer and director of this film, Babak Anvari, grounds it in his own experience of growing up in Tehran, and grates the nerves of his characters against the abrasively real. The lights don’t go out for no reason, in a bid to stoke the mood; they go out because of a power cut. And you don’t go underground to confront the bogeyman; you go there to avoid being bombed.