Did you know that Tom Hanks appeared in an episode of “Happy Days” in 1982? I wonder whether the actor’s recent performances in the Dan Brown adaptations The Da Vinci Code and Angels & Demons resulted from his crossing paths all those years ago with Ron “Richie Cunningham” Howard. If so, I would characterize the day of their meeting as a not-so-happy one.

For movie lovers and fans of Hanks and Howard, anyway. Both rank with the most beloved and accomplished figures in American cinema, but — let’s be honest — these two films represent perhaps the dumbest, most disposable work of their careers. In fact, to keep myself from dozing off during this latest bit of overwrought nonsense, I struggled to think of a role Hanks has played over the quarter-century of his stardom that is less worthy of him. I drew a blank.

Turner and Hooch (1989) comes close. In that film, as you may recall, Hanks played a detective whose partner was a constantly slobbering dog. Dumb and disposable as that was, Angels & Demons has it beat in both departments. Turner and Hooch, after all, was a comedy, while Howard’s latest is merely laughable.

Hanks once again stars as blabbermouth Harvard symbologist Robert Langdon. His partner on this case is a ravishing Italian physicist by the name of Vittoria Vetra (Ayelet Zurer), whose sole function in the picture is to talk whenever Hanks has to stop talking long enough to take a breath. If anything, Angels & Demons is gabbier than its predecessor — and that is saying a lot, so to speak.

Shortly after the death of a popular pope, Langdon is summoned to the Vatican to straighten things out. Agents of the Illuminati have stolen a canister of explosive antimatter from a Geneva lab, kidnapped four cardinals considered top contenders for the papacy, and threatened to blow St. Peter’s Square and its hundreds of thousands of denizens to kingdom come at the stroke of midnight. The Illuminati are members of an ancient, pro-science secret society who are still ticked off at the Catholic Church for persecuting Galileo in the 17th century. Talk about holding a grudge.

Langdon has mere hours to locate the ticking time bomb — though, this being a Dan Brown thriller, the canister hasn’t been hidden just any place. Illuminati members have taken great pains to stash it in a secret spot the professor can locate if he’s able to solve a series of riddles, puzzles and malarkey-filled mysteries in time. Those Illuminati may be sinister, but you’ve got to admit they’re pretty damned thoughtful.

This setup naturally necessitates much running around Rome, researching of archives and visiting of scenic tourist destinations. Mostly though, it involves talking. Hanks and Zurer blither like they’re getting paid by the arcane tidbit. Come award season, they really will merit special recognition for uttering the film’s silly, super-urgent dialogue with straight faces.

“The chapel is Raphael, but the statues are Bernini,” Langdon informs us in a typical scene, as though compelled to regurgitate information regardless of whether it possesses relevance to the story. When he’s not educating the viewer on the subject of ancient history, he’s predicting the future: “An obelisk! A kind of pyramid adopted by the Illuminati! If he’s going to kill, he’ll do it here!” More long, windy lessons in art history, science and church tradition follow.

The talents of Hanks and Howard are far from the only ones squandered here. Armin Mueller-Stahl and Ewan McGregor are also wasted in the roles of, respectively, a cardinal who may not be as pious as he seems, and a priest so charming and devilishly handsome he simply must be a good guy. Brown is not renowned for his subtlety, so when Surprise Twist Time finally rolls around, only the dim and dozing are likely to be caught off guard.

Let us pray this is the last Hanks-Howard-Brown collaboration with which audiences will be blessed. The summer blockbuster roll-out has barely begun. Nonetheless, if Angels & Demons doesn’t prove the biggest disappointment of the season, it will be nothing short of a miracle.