Thomas Olde Heuvelt is an international bestselling author from The Netherlands.

His breakthrough novel HEX was published in over twenty-five countries and hailed as 'totally, brilliantly original' by Stephen King and as 'phenomenal, phenomenal' by film director Mike Flanagan. His follow-up novels Echo and Oracle have since seen global publication, the former boasts, according to the Guardian, 'possibly the most frightening prologue ever written', while the latter was judged by The New York Times to be his 'sharpest, most compelling work to date'.

His newest novel, Darker Days, is a devastating modern take on the Faustian bargain. It will be published in the US with Harper Books and in the UK with Bantam in October 2025.

Olde Heuvelt, whose last name in Dutch dialect means 'Old Hill', was the first translated author to win a Hugo Award, in 2015.

He lives in the south of France with his partner and pet lizard.

Bantam Books, Penguin UK (first cover)

Harper, Harper Collins US (second cover)

Praise for Darker Days:

"Thomas Olde Heuvelt is back with another wicked, fascinating, chilling tale, expertly balancing the supernatural with the horrors inherent in human nature. Darker Days reinforces that Heuvelt is one of the most vital and exciting voices in modern horror."

Mike Flanagan, writer/director of The Fall of the House of Usher, Dr. Sleep, The Haunting of Hill House and The Life of Chuck

"Darker Days is a meticulous work of terror, a harrowing drop into a moral nightmare. If you can imagine the philosophical oomph of Bergman's The Seventh Seal joined to the rustic shocks of Midsommer, and all of it transported to America's suburbia, you'd have something like Darker Days. It's a scream."

Joe Hill, #1 New York Times bestselling author of King Sorrow

"No one builds agonizing tension like Thomas Olde Heuvelt. Darker Days is his best yet."

Catriona Ward, bestselling author of The Last House on Needless Street

"This masterly work of horror, gripping and terrifying on more than one level, is probably Olde Heuvelt’s best novel yet."

The Guardian

"The Netherlands-born author digs deep into the conflicts and consequences arising from the premise, his tale neatly and slyly probing the rotten roots of privilege, all the way to a gut-punching final twist."

Financial Times

"Stephen King is so associated with horror stories set in cozy small-town America, seamlessly blending pedestrian everyday living with supernatural dread, that it comes as a surprise that Darker Days is not from his pen....Utterly creepy and mesmerizing."
Irish Independent

"Darker Days is a remarkable and disturbing morality tale about the true cost of lucky lives. It’s a tremendous achievement by Thomas Olde Heuvelt as well as a frightening gift for readers."

Owen King, author of The Curator

"What price would you pay for a life of comfort, privilege and good luck? In Darker Days, Thomas Olde Heuvelt weaves a masterful modern fairytale that builds towards a horribly tense, shocking and devastating twist of sacrifice and disaster. You know it's going to be bad. Just how bad . . . let the wonderful Olde Heuvelt show you the way."

Tim Lebbon, New York Times bestselling author of Secret Lives of the Dead and 30 Days of Night

"The pursuit of happiness as an existential nightmare and a hellishly good read."

John Ajvide Lindqvist, International bestselling author of Let the Right One In

“The devilish genius behind HEX brings us a new collision of sly suburban satire and devastating folkloric nightmare. Darker Days is the perfect read for fans of Shirley Jackson, Sarah Langan, and stories you want to read from behind your fingers, as if that’ll somehow keep you safe from the escalating darkness.”

Nat Cassidy, USA Today bestselling author of When the Wolf Comes Home

“Darker Days is a classic horror story, but its deal-with-the-devil couldn’t be more timely. With a beautifully-rendered, struggling family and a murderous pact at its core, the suspense is killer, and the central question—what are you willing to do in exchange for your own comfort and happiness—is chilling and deeply disturbing. This one will haunt me.”

Christopher Golden, New York Times bestselling author of The Night Birds and Road of Bones

“Darker Daysis a novel of reckoning, calculating the balance between what you want and what it will cost, and a meditation on unthinkable bargains. An ingeniously constructed chronicle of fear from a master storyteller.”

Angela “A.G.” Slatter, award-winning author of The Crimson Road

"What price would you pay for a life of privilege? Darker Days is a new take on the Faustian bargain completely in keeping with our new age of greed and entitlement, with a twist at the end you won't see coming. This is Olde Heuvelt at the height of his powers."

Alma Katsu, Bram Stroker Award-winning author of Fiend and The Hunger

“Thomas Olde Heuvelt’s Darker Days begins on an uncomfortably grim and mysterious note. Olde Heuvelt increases the dread and tension over the course of this labyrinthine and distressing novel until the pressure is almost unbearable. There’s a distinctly unpleasant current of inevitability coursing beneath every page of this genuinely distressing work—the inevitability of ritual, retribution, sacrifice, and death. This is a daring and uncompromising jewel of horror fiction. Reminiscent of the flawless work of Stephen King, Michael McDowell, and Robert R. McCammon, but still completely its own singular and disturbing vision.”

Eric LaRocca, author of Things Have Gotten Worse Since We Last Spoke

"There are days where I can't help but wonder if Thomas Olde Heuvelt made a deal with the devil. His writing is so completely captivating, his forged worlds so engrossing and expansive, there has to be some soul-selling afoot. Darker Days is his Dr. Faustus on the grandest of scales, which makes Olde Heuvelt our modern day Marlowe."

Clay McLeod Chapman, author of Wake Up and Open Your Eyes and Ghost Eaters

"On the surface Darker Days is a deliciously grim and twisted fable about a bargain with a Devil. But it is also an unflinching examination of human nature and how easy it can be to look away from the suffering of others, which is a very timely and poignant reminder in this particular moment in time."

Hildur Knútsdóttir, author of The Night Guest

“Thomas is a great writer, the next genre superstar.”

Paul Cornell

"[Darker Days] presents a unique and interesting take on a dark deal and what the consequences could be. It will also challenge readers to think about what they would be willing to do for some luck..."

Booklist

"From the author of HEX, this novel twists the Faustian bargain into something fresh and fierce, soaked in atmospheric tension and moral complexity — a must-read for anyone who loves unsettling, character-driven horror....You’re in for something truly special."

Cinema Chords