One day Tom Hanks will get one of those lifetime achievement awards at the Oscars, and as the highlight reel of his career rolls, “Inferno” will appear far below “Turner & Hooch,” an interspecies buddy comedy that had him share the screen with a dog whose single trick was shaking his head in slow motion while giant trails of drool frothed from his massive jowls.

Or, if Hanks is lucky, “Inferno” will not appear at all.

It is hard to overstate how bad this abysmal film is. This is Hanks’ third round playing Robert Langdon, the hero of many unfathomably popular Dan Brown novels. A super-tourist and breaker of cryptic codes, Langdon is a sort of bland, Bostonian, not-at-all-tough Indiana Jones, another academic turned adventurer.

Hanks, hardworking and always game, spends his time on-screen without a moment of Harrison Ford swagger, instead wincing and flinching and fleeing danger. In “The Da Vinci Code” and “Angels and Demons,” he largely raced away from bad guys, and here he puts on his well-worn running shoes again. Scene after scene after scene after scene shows him sprinting to safety as fast as the film makes you want to bolt for the exit.

It opens with extended fantasy flashes — Langdon’s hallucinations of war and hellfire across centuries. They bear a pretty strong resemblance to the climax of “Raiders of the Lost Ark,” when Indy watched God melt the faces of numerous Nazis into corrosive ooze.

Here we see cities overrun by zombies with backward-facing heads, limbs from half-buried cadavers branded with rococo lettering and flash floods of blood exploding through office buildings like the elevators in “The Shining” in overdrive.

Don’t worry, Langdon is just having bad dreams, seemingly triggered by a bullet that grazed his art-history-filled skull and landed him in a hospital with temporary amnesia. He also has flashbacks to being violently syringed in the neck, visions that are only marginally more realistic.

This opens the door for scads of explaining. The scholarly hero has awakened in Florence because of a mysterious meeting concerning the death mask of Dante Alighieri, poet of the 14th-century narrative “Divine Comedy” (not 15th century, as they say in the film). Why is Landgon seeing those ooky apparitions and being chased by a scowling female killer disguised as an Italian cop? Because of something to do with a billionaire biochemist who committed suicide by leaping from the tower of a landmark church nearby. Since he is named Zobrist, played by the always intimidating Ben Foster, and ranted like an 007 villain in a broadcast tirade about doomsday overpopulation, he’s trustworthy, right?

Here we are again in Dan Brown World. Here businessmen are “radical,” the World Health Organization employs sharpshooting SWAT teams, secretive operations take place in travelogue tourist attractions and arcane mysteries are written crossword-style on artifacts hidden behind secret doors.

Anyway, someone has created a toxin like the Black Plague turned up to 11. A large amount of scientific-political-religious mumbo jumbo must be stopped before it is released and humanity is reduced by half. Langdon receives nonstop help from his young attending physician Sienna Brooks (Felicity Jones, whose utter lack of emotion makes me worry about her upcoming lead role in “Rogue One: A Star Wars Story”). They zip off to sightseeing treasures in Florence, Venice and Istanbul, pausing every 10 minutes to remind us why. The high point arrives when Langdon’s junior detective work makes him bawl, “We’re in the wrong country!”

While director Ron Howard keeps the action largely bloodless, this is a movie that delivers massive carnage and minimal thrills. Zobrist is not the only character to be dropped to bone-bashing doom at a top tourist sight; luckily the bodies tend to land in unusually empty galleries. Why not? Nothing here makes sense. Langdon gets concussed twice more, yet he can speed away on foot from motorbikes, police cars and a spy drone.

But for all of Howard’s jittery-cam video and hyper-drive editing, there is no exciting payoff. The sole winner in the slaughter sweepstakes is Indian superstar Irrfan Khan (“Life of Pi,” “Jurassic World”), as the ruthless leader of a mysterious assassination cartel. Khan plays the role without a speck of seriousness. Whether he is knifing opponents, swinging a crowbar into a downed rival’s head like a golf pro or handling Austin Powers-level plot exposition monologues, his minor character is by far the witty highlight of the film, the best thing on-screen before the end credits. “Inferno” manages to be overwrought and lackluster at the same time.