Would You Like Some Murder and Mayhem With Your Eggnog?

Daniel Sweren-Becker’s KILL SHOW (Harper, 240 pp., $27.99) is both an entertaining mystery and a bracing examination of how true crime has warped real-life investigations. It’s also a provocative reminder of how people behave differently, and often disastrously, when they’re in the spotlight.

Ten years after a lurid reality TV show turned the disappearance of a Maryland high school student named Sara Parcell into a national cause célèbre, a new oral history of the case has been published. (That’s the book we’re ostensibly reading.)

Using testimony from family, friends, law-enforcement officials, sociologists, pop-culture critics and others, the book lays out the unscrupulous approach of the ambitious reality TV producer Casey Hawthorne — responsible for a trashy dating show called “Arm Candy” — and how it changed everything.

But pretty much everyone is harboring an unsavory secret, behaving unethically or pursuing a selfish agenda. And as Casey points out, the book we’re reading is just as exploitative as her show.

“What a neat trick!” she says. “You get to pass judgment and turn a profit at the same time.”

Agatha Christie died many years ago, but Hercule Poirot, her lavishly mustachioed and extravagantly brainy detective, lives on in the British writer Sophie Hannah’s loopy whodunits, authorized by the Christie estate. In HERCULE POIROT’S SILENT NIGHT (Morrow, 384 pp., $30), the detective and his sidekick, Edward Catchpool, are summoned to a house in Norfolk at Christmas by Edward’s bossy mother.

This is unfortunate. “Life contained no greater struggle, for me at least, than time I spent in the company of my mother,” Edward says. But someone has been murdered, and Mrs. Catchpool’s friend is convinced that her own husband is to be the next victim. The book features a typically Hannah-esque collection of over-the-top neurotics, obsessives, fantasists and narcissists: feuding siblings, irrational parents, downtrodden in-laws. One improbable thing happens after the next.

Sometimes Hannah seems to be having more fun than the reader. But people who approach the book in the playful spirit in which it was written will appreciate her knack for hanging on to the essential mystery, no matter how many amusing distractions she throws our way.

Peter Swanson’s delicious new novella begins on Christmas Day in 2019, when a woman, alone in New York, cleans out her closet and finds an old diary from when she was an art student in London.

“I decide to take a look, not entirely sure that I’m prepared to go back in time to that annus horribilis, that murderous year,” she says, “but also knowing that once I start to read I won’t be able to stop.”

I defy you to stop reading THE CHRISTMAS GUEST (Morrow, 93 pp., $19.99) once you begin. (It’s short enough to gulp down in a single sitting.) The diary takes us back to 1989, when its narrator is invited to spend Christmas with a sophisticated British classmate at her family’s Cotswolds manor.

She is as excited as she is overwhelmed. The adults condescend to her; jokes soar over her head. She falls hard for her friend’s disreputable, seductive brother, even though everyone suspects him of a local girl’s unsolved murder.

She’s not worried, though perhaps she should be. “It’s looking like I’m in more of a murder mystery now than a romance. Or maybe I’m in both,” she tells her diary.

Maybe. The book gets darker and more shocking as it goes along. The twist will make you rethink everything you’ve read before.

How seriously can you take a whodunit whose characters are burdened with names like Hereward Trollope-Bagshott and Sir Rupert Achilles de Courcy Beauchamp? Charlotte Vassell’s THE OTHER HALF (Anchor, 353 pp., $27) is a satire of the young and the louche in London, as well as a mystery involving murder, money laundering and the dark implications of a charity named Help for Hippos.

The book starts as the aforementioned Rupert hosts a black-tie birthday party in the ironic location of a McDonald’s. Before the night is over, Rupert’s influencer girlfriend, Clemmie (known as Phlegm to her frenemies), has been found dead on Hampstead Heath, poisoned and stabbed.

Did Rupert do it? What about Clemmie’s boss, who was also her lover? What is the significance of a second murder, that of an older man who stashed a priceless antiquity in his mop bucket? And what awful thing happened between Rupert and Nell, the true object of his desire, on a trip to Greece?

One of the best things about the book is the affectionate relationship between its detective, Caius Beauchamp, and his law-enforcement colleagues. (He’s not related to Rupert, and his name is pronounced differently, reflecting his family’s lower social status.) Caius is an astute observer of behavior, criminal and otherwise.

“Caius had told enough people that their loved ones had perished, but he had never seen anyone be so uninterested, so bored by the news,” Vassell writes, of a conversation between Caius and Rupert. “No, wait, was that relief that flashed across his lips?”

A nasty February storm has cut off phone service at the remote MacKinnon Hotel in the Scottish Highlands, where Remie Yorke is working at the front desk. Suddenly, an injured man comes through the door, identifying himself as Police Constable Don Gaines and saying that he’s been in a car accident — and that the dangerously manipulative inmate he was transporting from the local prison has escaped.

The policeman is securing the premises when another injured man arrives, the title character in Martin Griffin’s THE SECOND STRANGER (Pegasus Crime, 300 pp., $27.95). In a dismaying turn of events, this new visitor also claims that he is P.C. Gaines — and that the first man is the escaped prisoner, Troy Foley. “This is what he does,” one of the men says of Troy. “He plays roles. He manipulates and confuses.”

Both men seem equally plausible, and equally implausible. Further complicating matters, one of the two remaining hotel guests seems to be surreptitiously recording his conversations with Remie, while the other has gone missing. Remie’s own memories, about a criminal brother who was killed in prison, contribute to a sense that she, too, is keeping secrets from the reader. Are any of them telling the truth, and will any of them get out alive?

Why do characters in thrillers feel compelled to return to the scenes of their worst traumas? In Luke Dumas’s THE PALEONTOLOGIST (Atria, 368 pp., paperback, $17.99), Dr. Simon Nealy foolishly takes a job at a struggling natural history museum — the very spot where his little sister, Morgan, disappeared on an outing with him when she was just 6 years old.

With its secret rooms and piles of uncataloged bones, not to mention its tendency to induce hallucinations (or are they?) in its employees, the museum feels less like “Night at the Museum” than “Night of the Living Dead” set at Jurassic Park. Also, it’s falling apart and hemorrhaging money because of the coronavirus pandemic. Simon is ordered to turn things around by mounting the dinosaur exhibition begun by his predecessor, Albert Mueller, who left under mysterious circumstances and whose descent into mental illness is chronicled in his increasingly unhinged research diaries.

After receiving a series of threatening notes and having an unhappy visit with his mother, who lives in a mental institution (“They’ve been waiting for you to come back,” she rants. “Evil, nasty terrible lizards!”), Simon has become a nervous wreck. When he sees a specimen in a diorama come briefly to life, he doesn’t know what to think. “It was as if the whole thing had never happened, the figment of a dark and disturbed imagination,” Dumas writes.

Sometimes the book veers off course a bit in its discussion of the library’s funding problems. But it’s erudite, atmospheric and at times genuinely creepy — a book to be read in bed, with the covers pulled tight.