It's been 42 years since Raiders of the Lost Ark introduced audiences to a boulder-dodging,Esthen globe-trotting, bullwhip-snapping archaeologist played by Harrison Ford. The boulder was real back then (or at any rate, it was a practical effect made of wood, fiberglass and plastic).

Very little in Indiana Jones and the Dial of Destiny, Indy's rousingly ridiculous fifth and possibly final adventure, is concrete and actual. And that includes, in the opening moments, its star.

Ford turns 81 next week, but as the film begins in Germany 1944, with the Third Reich in retreat, soldiers frantically loading plunder on a train, the audience is treated to a sight as gratifying and wish-fullfilling as it is impossible. A hostage with a sack over his head gets dragged before a Nazi officer and when the bag is removed, it's Indy looking so persuasively 40-something, you may suspect you're watching an outtake from Raiders of the Lost Ark.

Ford has been digitally de-aged through some rearrangement of pixels that qualifies as the most effective use yet of a technology that could theoretically let blockbusters hang in there forever with ageless original performers.

Happily, the filmmakers have a different sort of time travel in mind here. After establishing that Ford's days of derring-do aren't yet derring-done, they flash-forward a bit to 1969, where a creaky, cranky, older Indiana Jones is boring what appears to be his last class at Hunter College before retirement. Long-haired, tie-dyed and listening to the Rolling Stones, his students are awaiting the tickertape parade for astronauts returning from the moon, and his talk of ancient artifacts hasn't the remotest chance of distracting them.

But a figure lurking in the back of the class is intrigued — Helena (Phoebe Waller-Bridge), the daughter of archeologist Basil Shaw (Toby Jones) who was with Indy back on that plunder train in 1944. Like her father before her, she's obsessed with the title gizmo — a device Archimedes fashioned in ancient Greece to exploit fissures in time — "a dial," says Helena "that could change the course of history."

Yeah, well, every adventure needs its MacGuffin. This one's also being sought by Jürgen Voller (Mads Mikkelsen), who was also on that plunder train back in 1944, and plans to use it to fix the "mistakes" made by Hitler, and they're all soon zipping off to antiquity auctions in Tangier, shipwrecks in the Mediterranean, and ... well, shouldn't say too much about the rest.

Director James Mangold, who knows something about bidding farewell to aging heroes — he helped Wolverine shuffle off to glory in Logan — finds ways to check off a lot of Indy touchstones in Dial of Destiny: booby-trapped caves that require problem-solving, airplane flights across maps to exotic locales, ancient relics with supernatural properties, endearing old pals (John Rhys Davies' Sallah, Karen Allen's Marion), and inexplicably underused new ones (Antonio Banderas' sea captain). Also tuk-tuk races, diminutive sidekicks (Ethann Isidore's Teddy) and critters (no snakes, but lots of snake-adjacents), and, of course, Nazis.

Mangold's action sequences may not have the lightness Steven Spielberg gave the ones in Indy's four previous adventures, but they're still madcap and decently exciting. And though in plot terms, the big climax feels ill-advised, the filmmaker clearly knows what he has: a hero beloved for being human in an era when so many film heroes are superhuman.

So he lets Ford show us what the ravages of time have done to Indy — the aches and pains, the creases and sags, the bone-weariness of a hero who's given up too much including a marriage, and child — to follow artifacts where they've led him.

Then he gives us the thing Indy fans (and Harrison Ford fans) want, and in Dial of Destiny's final moments, he dials up the emotion.