On the dust jacket of the Spanish edition of Carlos Ruiz Zafón’s monumental final novel, “The Labyrinth of the Spirits,” the Catalan master storyteller, stares into the distance, as if he’s lost in thought, almost as if stopping to pose is an inconvenience, a waste of precious time.

His eyebrows arch and his jaw clenches ever so slightly. It is the look of an artist who has exhaustively wrenched from his imagination every word he placed on the page, yet still might be thinking of a few final tweaks.

For those who knew him, though, the eye is drawn to Ruiz Zafón’s left wrist, where he has strapped a heavy, impressive-looking watch that rests prominently near the center of the frame, just as he’d positioned other timepieces in previous portraits.

Ruiz Zafón — who died last week of cancer at the impossibly cruel early age of 55 — loved watches. He delighted in their precision, their complex interlocking parts, the ratchets and pinions and springs. His favorites were the ones with clear glass backs that he could study, tracking how the mechanisms lurched and spun, producing something that felt to him like a bit of magic.

Ruiz Zafón — the best-selling Spanish author since Cervantes and one of the most widely read writers in the world — conjured books with that same complicated structure, works that made sense only if you contemplated how the parts interacted with each other. His collection of four interrelated novels that culminated with “The Labyrinth of the Spirits” is often referred to as the Cemetery of Forgotten Books “series.” But in the long conversations we had over the past few years, Ruiz Zafón never used that word.

He preferred to call them a “cycle,” for he wanted to invite readers to dip into them at any point, following the spinning of the gears around the watch face whether they started at 3 a.m. or noon.

“To me, the original plan was to create this big kind of labyrinth of stories,” Ruiz Zafón told me one afternoon in 2018 shortly after his battle with cancer forced him to cancel a book tour marking the release of the English language edition of “The Labyrinth of the Spirits,” which like all the books in the cycle was elegantly translated by Lucia Graves.

“The more you explore it, the more you got inside of it, you could see that everything was shifting — that the story you thought you were reading actually was changing before your eyes.”

Ruiz Zafón situated his cycle of novels in Barcelona, the entrancing, mind-bending city where he was born. From his Los Angeles home, Ruiz Zafón could call up the tangled cityscape of Barcelona from memory. His was a Barcelona of mist and mystery. The ends of burning cigarettes flicker in the ghostly gloom of night in those dreary years after the Spanish Civil War. He propelled his characters through darkened walkways and slender streets — the names of which he rattles off by the dozens — in neighborhoods that the casual tourist might never think to visit.

I found myself recommending the book over and over to friends traveling to Spain who sought my suggestions, knowing I was born there. It opened their eyes to a Barcelona they would have missed if they’d only hit the beach and joined the hordes at La Sagrada Familia, the phantasmagoric cathedral designed by Antoni Gaudí.

“When we reached Calle Arco de Teatro,” says Daniel Sempere — the earnest protagonist of “The Shadow of the Wind,” the first and best-loved book of his cycle — “we continued through its arch to the Raval Quarter, entering a vault of blue haze. I followed my father through that narrow lane, more of a scar than a street, until the gleam of Las Ramblas faded behind us.”

Ruiz Zafón liked to say that he wasn’t into the social whirl — that he wasn’t a big talker. But, in one-on-one conversation, the words could come gushing out in bursts. He was a tall, lumbering man with enormous hands that paired well with his hefty watches, an owlish mien, and a dense circle beard. He looked older than his real age, perhaps because he’d packed so much into his too-short life, working first as a handsomely paid adman, then writing young adult fiction before turning to his most enduring work, the Cemetery of Forgotten Books cycle.

He will surely always be associated with Barcelona. But he wasn’t writing travelogues. It was the characters whom he placed in its winding corridors — the bookseller with a monocle, the menacing Franquista thug, the verbose ne’er-do-well, the vanishing novelists — and the alchemy of his storytelling, that elevated his work, including the middle books in his cycle, “The Angel’s Game” and “The Prisoner of Heaven.”

He combined elements of gothic novels — all flickering candles, creaky mansions and advancing shadows — with a coming-of-age story, noirish mysteries, meditations on the legacy of the brutal dictatorship of Generalissimo Francisco Franco and the fallibility of memory. The sprawling novels encompassed everything, so they spoke to everyone.

For all their cinematic qualities, Ruiz Zafón had steadfastly resisted any attempts to adapt his books into movies. He told me over lunch at a Washington restaurant in 2016 that he planned to put a clause in his will to ensure his wishes would be enforced even after he was gone.

Readers, he said, have “already seen the film in the theater of their mind in exactly the condition I want them to experience it in.”

Ruiz Zafón often turned to the piano, composing musical pieces for many of his characters, a process that he felt allowed him to understand them better.

In Sempere, Ruiz Zafón poignantly brought to life a boy who could no longer remember the face of his dead mother. It is through Sempere’s 10-year-old eyes that we first behold the Cemetery of Forgotten Books, a labyrinth of bookshelves that “rose from base to pinnacle like a beehive.”

His visit to that secret redoubt sets in motion a quest for answers that unveils a dark past. Just as Sempere guides us through a gritty Barcelona of bygone days, his son, Julián, nudges us to reckon with what Barcelona has become.

“I learned to rediscover the city,” Julián muses to himself. “The world I once imagined I could remember now lay dismantled. It had become a stage set, perfumed and carpeted for tourists.”

Ruiz Zafón was not wistful when he finally closed his cycle, having tinkered with even minute details until the music of the words matched the music in his head. He’d once thought he’d write a single gargantuan book, a 2,000-page behemoth, but cracking the story into four parts made the most sense to him.

“It would have been a monstrosity,” he told me, his thinning voice rising an octave and striking a note of whimsy. “People would have died underneath it if it fell off the shelf.”

(He skipped over the fact that the original Spanish-language edition of “The Labyrinth of the Spirits,” published in 2016, might be, at the very least, capable of causing injury, clocking in at 925 pages.)

During the conversation, the tone of his voice eventually shifted. He became reflective and searched for the right phrasing to explain why the end wasn’t really the end. Not for Daniel Sempere, or the impish Fermín Romero de Torres, or the elusive literary genius Julián Carax, or the morally conflicted Secret Police investigator, Alicia Gris.

In their final renderings, Ruiz Zafón told their stories with chapter titles drawn from the sections of the Catholic Requiem Mass. But, in his mind, he didn’t bury them.

“It’s not like they’re going away,” Ruiz Zafón told me. “To me, they live inside my head. To me, the door was never closed.”