“Mission Impossible – Dead Reckoning Part One,” which is 2 hours and 43 minutes long (just typing the title is exhausting), is the sequel to “Mission Impossible – Fallout” (2018) and the 7th film in the MI series. “Dead Reckoning, Part Two” was filmed alongside “Part One.” The series began in 1996 (Cruise was 34). Are your arteries hardening as you read this? It’s based on the 1960s CBS television show with an ensemble cast and a thrilling, instrumental theme song composed by Lalo Schifrin.

The new film’s cast is still led by 61-year-old Tom Cruise, still doing his own stunts, Rebecca Ferguson returns as the outlandishly-named Ilsa Faust, also Ving Rhames as tech wizard Luther Stickell, scene-stealing Simon Pegg as another tech wizard and a master of disguise Benji Dunn, and Henry Czerny is back as IMF head Eugene Kittridge. Vanessa Kirby, looking out of her mind most of the time, returns as the ”White Widow,” Alanna Mitsopolis, an arms dealer who cares not about the consequences of her work. The always welcome Shea Whigham (“Joker”) is dogged agent Jasper Briggs on the trail of Cruise’s Ethan Hunt. London-born Hayley Atwell, who is a big asset in a film dearly in need of one, plays a master thief named Grace. Atwell and Cruise, who were rumored to be an item, team up for the film’s most spectacular scenes. Esai Morales plays the film’s shadowy antagonist Gabriel.

This time around Hunt and his team are after a key that you will get tired hearing about. It unlocks the modern-day equivalent of Pandora’s box. That is an “entity” that can spread to and take over all digital systems and devices and sounds a lot like artificial intelligence (AI). In a substandard (pun intended) version of a James Bond opening, a Russian submarine encounters an adversary in the Bering Sea.

In Amsterdam, we are reminded of Hunt’s “habitual rogue behavior,” which is why we love him so much, right? Suddenly, we and Hunt are in a shootout on horseback in a sandstorm in an Arabian desert with Hunt and faceless warriors who cannot shoot straight. Luckily, for Hunt, Ilsa can. How many cliches can the screenplay by Erik Jendresen (“Killing Lincoln”) and director Christopher McQuarrie (“Top Gun: Maverick”) squeeze into a single sequence? A lot. A scene set in D.C. plays like a TV series with an ensemble cast. The actors wearily toss the dialogue “ball” to one another, and in this case such talented players as Rob Delaney and Indira Varma sound like zombies.

At this stage, Cruise’s face is no longer boyish. While he sports the same haircut and not a speck of gray, his face has begun to sag, and he’s gotten jowly. Cruise doesn’t really act. He’s a star. He just is. Has the pulling-off-the-rubber-mask reveal stunt gotten old yet? It never worked for me.

Most of the film’s action scenes, including one aboard the fabled Orient Express and evoking Buster Keaton’s 1926 Civil War-set silent film landmark “The General,” are admittedly very well done. But whenever someone opens their mouth to speak the dialogue, you want to shoot yourself. Someone says, “stupid clown show,” and I thought, hmm. That could be my headline. On a motorcycle, Cruise is good. But he’s no Steve McQueen. In Venice and Rome, the scenery upstages the film. Pom Klementieff (“Guardians of the Galaxy”) is impressively athletic as French-speaking assassin named, yes, Paris. The writers borrow from everyone from Jason Bourne to Alfred Hitchcock. A small nuke requires answers to riddles to disarm it. Where is Monty Python when you need them?

(“Mission Impossible – Dead Reckoning Part One” contains violence, harsh language and suggestive material)

Rated PG-13. At the AMC Boston Common, AMC South Bay and suburban theaters. Grade: C+