It's ten years since Tom Hanks first played the dull but exceedingly well-read Robert Langdon in The Da Vinci Code, and seven since he did another lap of art-history orienteering in Angels and Demons.
That time lag might suggest a lack of urgency in getting to Inferno, Hanks' and director Ron Howard's third Dan Brown adaptation. And that maybe even the participants are tired with Brown's historic conspiracy puzzlers.
Langdon, as the business class Indiana Jones, is called on again to be the smartest guy in the room. Albeit in some very nice rooms - for all its tedium, Inferno is a sightseeing treat as it flits from various galleries, churches and palaces in Florence, Venice and Istanbul.
But while the previous films had some pace and felt like there was something at stake in the Christianity versus science mumbo jumbo, this one is leaden in almost every department.
Watching it feels like signing up to a tour group visiting the sites of Brown's less popular works and you're not allowed off the bus.
Though there is a new twist, of sorts. Langdon's very big brain is on the blink after he's woken up in a Florence hospital not remembering how he got there. Neither can he remember why someone apparently wants to shoot him or why he's having apocalyptic visions involving the Black Plague, a Ted-talking billionaire biochemist with the not-at-all-evil name of Zobrist and Dante's Divine Comedy and its nine circles of hell, all chucked into the CGI hallucination blender.
So not only does Langdon have to figure stuff out before that billionaire biochemist carries out his pet project, he has to figure out who the good guys are.
He's got help in the form of Felicity Jones as a helpful doctor, who, it seems, knows both Langdon's work and her Dante.
Together, they spend most of the movie trying to find yet another exit in yet another labyrinthine Italian tourist trap while being pursued by, among others, Elizabeth Sinskey (Sidse Babett Knudsen), an old flame of Langdon's. She's in charge of the World Health Organisation's hit squad whose budget extends to crack troops and private jets.
The last third of the film involves a hasty flight on one of them from Venice to Istanbul. But it's been heading toward Turkey all along.
Cast: Tom Hanks, Felicity Jones, Sidse Babett Knudsen, Ben Foster, Irrfan Khan
Director: Ron Howard
Rating: M (violence and offensive language)
Running time: 121 mins
Verdict: Hell of a bore