In 2001 he published his first adult novel La sombra del viento (The Shadow of the Wind, Lucia Graves’ English translation published in 2004), a Gothic mystery that involves Daniel Sempere’s quest to track down the man responsible for destroying every book written by author Julian Carax. The novel has sold millions of copies worldwide and more than a million copies in the UK alone. Since its publication, La sombra del viento has garnered critical acclaim around the world and has won many international awards.

Ruiz Zafón’s next novel, El juego del ángel, was published in April 2008. The English edition, The Angel’s Game, was also translated by Lucia Graves. It is a prequel to The Shadow of the Wind, also set in Barcelona, but during the 1920s and 1930s. It follows (and is narrated by) David Martín, a young writer who is approached by a mysterious figure to write a book. Ruiz Zafón intended it to be included in a four-book series along with The Shadow of the Wind.

The next book in the cycle, El prisionero del cielo, appeared in 2011. It returns to The Shadow of the Wind’s Daniel Sempere and his travel back to the 1940s to resolve a buried secret. The novel was published in English in July 2012 as The Prisoner of Heaven.

The Labyrinth of Spirits (original title: El laberinto de los espíritus) is the fourth and final book in the Cemetery of Forgotten Books series. The novel was initially released on 17 November 2016 in Spain and Latin America by Spanish publisher Planeta. HarperCollins published the English translation by Lucia Graves, which was released on 18 September 2018.

On 19 June 2020, at the age of 55, Ruiz Zafón died of colorectal cancer in Los Angeles.