The thing about Professor Robert Langdon is, he’s solving mysteries none of us has a prayer of solving before him. He’s not playing fair.

Novelist Dan Brown’s “Da Vinci Code” “puzzle-master,” classics professor and antiquities expert, has information in his memory banks that can uncover an alteration to any painting, a clue within any line of ancient poetry, with just a glance. Like any of us has Dante memorized, or a photographic memory of mural-sized masterworks about epic battles of the Middle Ages.

Langdon’s wits and clue-connecting is unmatchable, even after he’s suffered a head wound and suffered days of memory loss, a plot device in “Inferno,” the latest Brown novel about Langdon’s exploits to make it to the Big Screen. Add to that the cheats and red herrings the story tosses our way, and we’re totally at a disadvantage. We can’t solve the puzzle before Langdon, because the pieces are changed to ensure that he’s the only one who could put all this together.

That said, Ron Howard, his star Tom Hanks and an A-list production team make this third “Da Vinci” film a solid page-turner, a travelogue that has a bit more logic about it and a more convincing villain than the truth-obscuring Catholic Church of the first two films. Really, if you think the Mother Church is fretting over any secret that doesn’t involve child-raping priests and dictator-coddling popes, you’ve got a richer imagination than Brown.

Hanks’ Langdon is found, in a Florence hospital, hallucinating nightmares ripped straight from the pages of Dante’s “Inferno,” a seven-hundred year old vision of Hell that Lagndon’s foggy short-term memory tells him is in danger of coming true on Earth.

Because there was this billionaire Zero Population Growth Messiah, a TED talk terrorist (Ben Foster) who just died and whose dying gift to the world was a global plague which only Langdon can prevent. Because, you know, the billionaire built this bio-engineered cataclysm on a ticking clock and a puzzle which his True Believers and a classics scholar would be able to decode and either launch or prevent.

An assassin (Ana Ularu) is after him. A “provost” (Irrfan Khan) seems to be pulling the strings from his offshore (ship borne) supervillain’s lair. And Langdon’s best hope is the English doctor (Felicity Jones of “The Theory of Everything”) who helps him escape assassination, the World Health Organization agent (Omar Sy) on his trail, and perhaps the CIA and others who might want to know what he knows.

And most paranoid of all, Langdon has no clue about who to trust and doesn’t know the black guy chasing him is a U.N. representative.

Hanks is as intrepid as ever as Langdon — no James Bond or “Terminator,” just a smart guy with a lot of experience in Florence’s museums, great houses and secret passages, just enough to keep him ahead of Sy (“The Intouchables”), who has only youth, strength, stamina and a World Government organization at his fingertips.

Foster makes a believable cultist, a smart guy taken way too seriously by virtue of his sudden wealth. He is TED Talks’ sins incarnate. Jones is plucky, a good character to have the plot points “explained to” by Langdon (who remembers little) and those who help him piece together the past few days so he can figure out what he’s looking for, and where in history he might find it.

The most interesting character and performance come from the great Indian actor Iffran Khan (“Life of Pi,” “Jurassic World,” “The Lunchbox”). He brings a wonderful world weariness to this “dark money” criminal mastermind.

“You people are a disappointment. I find they become tolerable around 35.”

Which is something like the selling point of this thriller, an old fashioned “mystery” with mostly over-50 actors and their yarn stealing the box office thunder from caped crusaders and their ilk for one week in the fall.

Brown is a forgettable writer and the films Howard has made from his books have lovely locations — Florence, Venice and Istanbul this time — and classic writers and painters (Dante’s “Inferno” and his death mask, Boticelli’s paintings — that rescue them from the simple hokum that he’s inclined to serve up.

On the whole, though, “Inferno” is less interesting because it’s a little more believable, at least in that “highly improbable/entirely possible” James Bond movie sense.

The puzzles are bigger cheats, the clues less striking (Da Vinci is hard to beat as a “puzzle master”) and the resolution as eye-rolling as ever.

And Langdon, that man of letters, simply has too much in his arts ed background for us to be able to keep up with him every time he recites this movie’s Latin mantra — “Cerca Trove — Seek, and ye shall find.” It’s just not fair that he’s the only one who has a prayer of finding what we’re all seeking, because the plot shifts to give him even more advantages than his prodigious memory and classics education should warrant.

MPAA Rating:PG-13 for sequences of action and violence, disturbing images, some language, thematic elements and brief sensuality

Cast: Tom Hanks, Felicity Jones, Omar Sy, Ben Foster, Irrfan Khan, Sidse Babett Knudsen

Credits:Directed by Ron Howard, script by David Koepp, based on the Dan Brown novel. A Sony release.

Running time: 2:01