Inferno Book Review: Dan Brown’s Most Thought-Provoking Langdon Novel

Inferno Book Review: A Thriller Based on Place

As the first three books in the series have taught us, Robert Langdon has never been known for calm vacations, but Inferno might be the most disorienting journey of them all.

The fourth novel in Dan Brown’s Robert Langdon series opens with Langdon waking up in a Florence hospital with a head wound, no memory of the last several days, and the unsettling sense that someone is hunting him. Outside his window is a skyline he recognizes instantly (Florence!) one of the most art-saturated cities in the world. 

From then on, Inferno becomes a breathless chase through Florence, Venice, and Istanbul, stitched together by Dante’s Divine Comedy, Botticelli’s eerie “Map of Hell,” and the growing fear that a brilliant geneticist has taken drastic action to “save” humanity from overpopulation. Dan Brown opens with a chilling line: “The darkest places in hell are reserved for those who maintain their neutrality in times of moral crisis.” (Unfortunately, that quote is still very fitting in today too.)

As someone who lives in Italy (quite close to Venice) and has visited Istanbul, I love that Inferno is basically a thriller wrapped around a travel itinerary. Like others in the series, this is a book that doesn’t just reference famous locations it actually makes the cities (and all that they offer) crucial to the plot.

Keep reading for my full Inferno book review that includes a lot of info on the included locations, the characters, and some of the main themes and ideas.

(For a refresher on the series, be sure to check out my Robert Langon Series Overview.)

The Cities That Shape Inferno’s Plot

As usual, Dan Brown leans heavily into real-world geography, architecture, and art history giving us a novel that makes us want to pull up a map alongside the chapters.

So, of course, one of my favorite aspects of Inferno is how vividly it brings real places to life. Because these are cities I know firsthand, the descriptions feel especially real and it’s easy to imagine retracing Langdon’s steps.

Unlike some books where locations might be interchangeable, the settings in Inferno are are crucial to the story’s puzzles and themes. Each city contributes something distinct — visually, historically, and symbolically — to the narrative.

Florence, Italy

Much of the novel unfolds in Florence’s historic center, and Brown makes full use of the city’s long and layered history. Langdon flees through narrow streets near the Badia tower, ducks into churches, and races toward the Palazzo Vecchio, whose fortress-like façade and replica of Michelangelo’s David stand guard over the Piazza della Signoria.

Inside the Palazzo Vecchio, we visit the Hall of the Five Hundred and the Hall of Geographical Maps, where art and hidden symbolism become integral to the puzzle itself. Brown also lingers on Florence’s most famous landmarks — the Duomo, the Baptistry of San Giovanni with its gilded “Gates of Paradise,” and the Vasari Corridor, the elevated passageway connecting the Palazzo Vecchio to the Pitti Palace and Boboli Gardens.

I’ve now read this book twice and I recently read it just a few months after visiting Florence, so I was especially struck by how accurately Brown captures the feeling of Florence: beautiful, overwhelming, clearly full of history…and slightly claustrophobic when you imagine being chased through it.

(To see the main sights in Florence in one day, I highly recommend this tour: Florence: Highlights Walking Tour with Expert Guide)

Venice, Italy

From Florence, the story spills into Venice, a city well-known for mystery and decay. Langdon follows clues along the Grand Canal, rides a vaporetto, and moves through landmarks like St. Mark’s Square, the Doge’s Palace, the Bridge of Sighs, the Rialto Bridge, and even Harry’s Bar.

Venice’s historical relationship with the plague plays directly into the novel’s themes. Brown uses the haunting imagery of Carnival-era plague masks (the ones with long, beak-like noses, not the pretty elegant ones you might be thinking of) to reinforce the book’s obsession with disease, fear, and humanity’s attempts to control its own survival.

Venice often feels fragile and haunted, and especially in Inferno: it’s a perfect bridge between the Renaissance past and the ethical nightmare the story is racing toward.

(The best part of Venice, though, is just wandering and getting lost amongst the canals, but I do recommend this tour for an insider’s look of St. Mark’s Basilica, Doge’s Palace, and the Bridge of Sighs.)

Istanbul, Türkiye

The novel’s climax takes place in Istanbul, a city that feels like a natural culmination of the book’s themes. Beneath and around Hagia Sophia and the Basilica Cistern (often called “the sunken palace”) the story reaches its most intense…and unsettling…moments.

Istanbul’s position between Europe and Asia, between empires and belief systems, mirrors the moral crossroads at the heart of the novel. Brown weaves in locations like Topkapi Palace, Sultanahmet Park, and the ancient obelisks, reinforcing the idea of Istanbul as a city built on layers of history, conquest, and contradiction.

Having visited the cisterns in person, I can say this setting is one of Brown’s strongest. The atmosphere is eerie, disorienting, and unforgettable…and it matches the story perfectly.

(To really see the underground cisterns that are such a part of the story, get these tickets for fast-entry and an audio guide.)

Inferno’s Most Important Characters

At the center of Inferno is, of course, Robert Langdon; but this version of Langdon feels different than in the previous three books. His amnesia takes away his usual calm authority, forcing him to act on instinct and trust people he doesn’t fully understand. That vulnerability adds tension and makes him feel less like an untouchable genius and more like a man scrambling to catch up.

I found Dr. Sienna Brooks to be one of the most intriguing characters Brown has written. Her background as a child prodigy — memorizing plays overnight, mastering languages, and outpacing adults from an early age — gives her brilliance a lonely, isolating feeling. She’s reserved, deeply intelligent, and emotionally complicated…and her connection to the book’s central ideas gives the story much of its weight.

Bertrand Zobrist, the biochemist whose work drives the entire plot, is technically dead before the story begins, but he looms over every chapter. Through recordings and secondhand accounts, Brown presents a man who is horrifying not because he’s irrational, but because he’s chillingly logical. His views on overpopulation are framed as mathematical inevitabilities rather than moral arguments, which makes his “solution” eve more disturbing.

Supporting characters like Elizabeth Sinskey, the director of the World Health Organization, and the Provost of the shadowy Consortium represent different forms of institutional power and they raise uncomfortable questions about responsibility, neutrality, and the cost of inaction.

Themes & Big Questions

Beneath the chases and riddles, Inferno is wrestling with one main question: what happens when humanity refuses to confront the consequences of its own growth?

Zobrist argues that overpopulation will inevitably lead to famine, conflict, and collapse, and that denial is humanity’s greatest flaw. His perspective is extreme, but Brown doesn’t allow readers to dismiss it easily–he actually makes some thought-provoking (though disturbing) points. Instead, the novel forces us to sit with the discomfort of choosing between terrible options.

The book also dives into transhumanism–you’re probably familiar with the idea, but maybe not that name: it’s the idea that humans should use technology, like genetic engineering, to move beyond natural limits and create ideal humans.

One of the most haunting ideas in the novel is a recurring moral thought experiment: if you could flip a switch that would save humanity in the long term but kill millions immediately, would you do it? Inferno never offers a clean answer, and that ambiguity is part of what makes it sticks around in your mind (and is what makes it great for a book club discussion, so check out my Inferno Book Club Guide.)

My overall impression: this might not be everyone’s favorite Langdon book from a pure plot standpoint, but in terms of sense of place and the weight of its ideas, I thought it was one of the strongest.

Bottom Line Book Reivew: Is Inferno Worth Reading?

Inferno is one of those novels that makes you want to book a trip and start an argument at the same time.

It may not be every reader’s favorite Langdon book in terms of pure plot mechanics, but in terms of atmosphere, sense of place, and the weight of its ideas, I think it’s one of the strongest in the series. It’s especially well-suited for book clubs, where the ethical questions and controversial ending naturally spark debate.

If you enjoy fast-paced thrillers that double as travel inspiration — and if cities like Florence, Venice, and Istanbul already fascinate you — Inferno is well worth reading. It’s a story that stays with you, not just because of where it goes, but because of the questions it makes you think about.

And, of course, you should watch the 2016 film adaptation (read my Inferno Movie Review) to literally see the story come to life.