Books like Relentless by Dean Koontz

Tina Evans, reeling from her son Danny’s death, prepares a Las Vegas show and discovers a cryptic note—’NOT DEAD’—that forces her into a dangerous investigation across the High Sierras.

A boy with broken memory wakes in a stone‑walled maze, where he meets other children who call it the Glade. When the first girl arrives, secrets about survival, cooperation, and the maze’s mystery begin to surface.

The Passage is Justin Cronin’s 2010 debut novel that blends science‑fiction, horror, and dystopian themes as it follows humanity’s struggle against a virus‑transformed vampire‑like threat.

When a murderous sociopath stalks her friends in Napa Valley, former survivor Chyna Shepherd must guard herself and an innocent stranger, risking life and sanity to confront the deadly intensity of Edgler Vess.

In the secluded town of Snowfield, California, a shocking mystery unfolds after 150 people are found dead with grotesque injuries, sparking a chilling investigation into a mass murder that blurs the line between good and evil.

With a rare gene that renders him hypersensitive to light, Christopher Snow navigates the shadows of Moon Bay, California, until a series of sinister events forces him to confront danger and the town’s hidden truths.

In Dean Koontz’s thriller "Watchers," a genetically engineered dog gains human intelligence, stirring a deadly conflict when it escapes, endangering those who cared for it and unleashing a state‑level secret.

When a sterile silver rain engulfs a quiet Californian mountain town, a couple and neighbors discover that all communication has vanished and a hidden menace now stalks them, unveiling an apocalypse that threatens the world.

Two isolated individuals flee a clandestine, illegal agency with a secret fascist agenda, chased by a ruthless operative who wields full governmental power.

After a bartender is selected by a serial killer, William Wiles must decide who will be murdered next, racing against time and increasingly brutal demands to save lives.

Roman fantastique. Roman policier (suspense).

During the Edinburgh Festival, a roadside road‑rage incident turns a bystander, ex‑army officer Jackson Brodie, into a suspect, sparking a detective mystery that waltzes between fortune and self‑discovery.

Two men on a road trip find themselves chased by a dangerous, mentally unstable killer.

Adam Lang, Britain's controversial prime minister, hires a new ghostwriter to complete his memoirs. However, the newly assigned writer discovers an even darker past and deadly secrets that put the entire country in danger.

447 pages : 24 cm

"I very much need to be dead." These are the chilling last words left by a man who had everything to live for but took his own life. In the void that remains stands his widow, FBI agent Jane Hawk, surrounded by questions destined to go unanswered unless she does what all the grief and fury inside her demand: Find the truth, no matter what. People of talent and accomplishment, people seemingly happy and sound of mind, have recently been committing suicide in surprising numbers. A disturbing pattern is beginning to emerge. Jane is determined to give up everything to find out why. And if that means going rogue and becoming America's Most Wanted, then so be it. Those arrayed against her are legion, and devoted to protecting something profoundly important-or terrifying-enough to exterminate any and all in their way. But Jane is as clever as these enemies are cold-blooded, as relentless as they are ruthless. And she is driven by a righteous rage they can never comprehend. Because it is born of love.

Cecilia Fitzpatrick’s flawless life unravels when she discovers a letter from her husband meant only for after his death. The secret threatens to shatter her marriage, her community, and the closely guarded lives of her closest friends.

Guy, his wife, and his mother-in-law: a wild and funny saga of love, loss, and literature gone wrong

A novel exploring the final years of a renowned writer caught in the conflict between his beloved wife and the Tolstoyan movement, with a compelling portrayal of a genius at the crossroads of his life and legacy.

A literary thriller about two men living in a world of fiction, words, scenes, characters, and the New York Times bestseller list, featuring a complex plot involving deception, envy, and the power of the written word.

Dean Koontz, a prolific American author, known for his unique cross-genre style and his personal struggle with mental illness and his father, is celebrated for blending suspense with literary elements.

A woman entwined in a thriller unfolds a haunting manuscript that drags her into her ex‑husband’s past and a web of fear, regret, and revenge.