Prior to 'Mr. Mercedes', King had written mystery novels but felt uncertain about the reception of this new direction, which lacks his usual fantastical elements.

King expressed his doubts about how readers would react to this shift, stating it felt like a 'fork in the road' for his career.

The story features Clyde Umney, a detective who discovers he is fictional and must switch lives with his author, showcasing King's exploration of the relationship between creators and their creations.

King also discusses his short story 'Umney’s Last Case', which examines the existential dilemmas faced by fictional characters, inspired by classic detective shows like 'Mannix' and 'Magnum, P.I.'

Although 'Umney’s Last Case' was published in 1993, it remains a celebrated piece of King's work, particularly for its clever narrative and the successful adaptation in the 2006 anthology series 'Nightmares and Dreamscapes'.

Holly Gibney, initially intended as a minor character, has featured in multiple works beyond 'Mr. Mercedes', including 'The Outsider' and her own titular novel released in 2023.

Stephen King reflects on how the publication of 'Mr. Mercedes' in 2014 marked a significant turning point in his writing career, shifting his literary profile towards crime fiction.

Despite initial anxiety about the reception of this straightforward detective story, King decided to pursue the book due to the compelling flow of ideas he had, emphasizing the importance of following his creative instincts over audience expectations.

In 'Mr. Mercedes', a retired cop engages in a cat-and-mouse game with a deranged killer who uses a stolen Mercedes to commit murder, representing a departure from King's typical horror themes.

The novel was well-received and led to the creation of a trilogy, introducing the character Holly Gibney, who has since become one of King's most notable characters.