Why are so many new novels set on trains?

“There isn’t a train I wouldn’t take, No matter where it’s going.”

That dandy epigraph, from Edna St. Vincent Millay’s poem “Travel,” begins Emma Donoghue’s entertaining new novel. “The Paris Express” gets much of its momentum from the relentless energy of a train. Both the epigraph and Donoghue’s book, which is in stores Tuesday, beautifully capture the thrill and romance of train travel’s heyday.

Two other 2025 titles, Alex Schulman’s “Malma Station” and Riley Sager’s upcoming “With a Vengeance” are, like “Paris Express,” set all or largely on trains, and they, too, are in good company. Ranging from Agatha Christie’s classic “Murder on the Orient Express,” in which a train populated by potential killers is stalled in a snowdrift, to Kotaro Osaka’s much speedier “Bullet Train,” all of these books reveal that a lot of bad things can happen when you get on a train.

For one thing, you pretty much can’t get off unless officials tell you to, which means there’s the potential for conflict and terror. Writers can also sneak a lot of story into books that cover the kind of territory a train ride does. The “Paris Express,” for instance, takes readers from the Normandy coast to the French capital, with Donoghue describing lots of the terrain along the way and noting “the paradox of trains,” which is that “they show you what you’d never see otherwise, but only for a tantalizing second.”

That could almost work as a description of another train-set Christie book, “What Mrs. McGillicuddy Saw!,” in which a woman is certain she witnessed a murder on a train as it sped away from her (something similar happens in the wildly popular “The Girl on a Train”). But even if no one witnesses a murder, trains pay dividends as settings for novels because they contain so much drama: people saying hello, people saying goodbye, business being transacted, lives changing forever, the connections made possible by new passengers constantly getting on and off.

Donoghue nods to that in “Paris Express” with a meta, train-within-a-train touch: One of her characters, heedlessly hurtling toward a possible explosion, indicates that “generally she enjoys stories about the railways — lovers just missing assignations or hurling themselves under the wheels."

This fall’s “6:40 to Montreal” could be the murderiest of all the train books, with a mystery writer on board a train packed with maniacs and a pile of bodies. That level of tragedy doesn’t happen in every train novel, of course. But these three train books reveal there are a lot of different kinds of danger:

Malma Station, Alex Schulman

The dangers are emotional in the non-chronological “Malma Station.” Events keep looping back on themselves, as a way for the Swedish writer to capture the dislocation and chaos of trains and train stations. Characters in “Malma” are constantly missing their stops or leaping on trains without tickets and even the ones who settle comfortably into their seats usually follow that up with travel-induced, anxious bickering.

“Malma” has three main characters, whose stories we gradually realize are related: a girl named Harriet, a man named Oskar and a woman named Yana. The book opens with a devastating, weirdly beautiful check-in on Harriet, who has overheard her divorcing parents argue about which of them will take Harriet’s sister and which will get stuck with her.

Although her parents don’t know it, Harriet is the book’s most appealing character because she has it so rough and because her response to this is so un-self-pitying. Schulman pulls us immediately into her feelings of loss with passages like one in which not only does she fail to feel sorry for her own plight but she also expresses sympathy for her father, because he didn’t get the child he wanted.

Schulman’s spare writing, translated from Swedish by Rachel Willson-Broyles, drills to the core of his complicated characters and by the end, after we’ve revisited incidents — on the train and off it — from all of their perspectives, it feels like we understand every one of them.

The Paris Express, Donoghue

The premise is irresistible: The whole book takes place on the several hours of a French train ride in 1895 and, very early on, we learn that one of the passengers is an anarchist who plans to blow up the train. We meet a dozen or so characters and fret about their fates, knowing what may be in store for them, so the suspense keeps building and building. It’s slightly dimmed by the fact that Donoghue chooses to include some real-life characters (including filmmaker Alice Guy-Blaché and painter Henry Tanner). We know they’re going to survive to create their best-known work, but Donoghue regains her tale’s immediacy by including an actual photo from the incident that inspired her fictional retelling.

With a Vengeance, Riley Sager

There’s more than a hint of “Murder on the Orient Express” in Sager’s gripping novel, due in June. It’s the 1940s and, as in “Orient Express,” a woman has invited the people she believes wrecked her family to travel on a luxury train from Philadelphia to Chicago. She’s bent on revenge but someone beats her to it, murdering a fellow passenger and hinting at plans to keep going until the train is empty. (Which, come to think of it, makes it a mash-up of “Orient Express” and “And Then There Were None.”)