Woody Allen’s oft-repeated modus operandi is that he has an idea, jots it on a slip of paper, shoves it into a desk and then takes it out later and makes a movie out of it.

What was on the the slip of paper that led to “You Will Meet a Tall Dark Stranger”?

“Round up the usual stars in my thrall, move to London for a stretch and bore them and the audience to tears?”

A mirthless, joyless comedy with nary a hint of romance,  mystery or justification for its existence, it joins “Hollywood Ending,” “Anything Else,” “Whatever Works,” Cassandra’s Dream” and other recent clunky, tone-deaf Allen films that plainly should have remained weak, undeveloped ideas tucked inside that infamous desk.

The dotty Helen is where we “begin,” our bored narrator tells us. She (Gemma Jones) has gone to a mentalist as a way of keeping her out of her daughter (Naomi Watts) and husband Alfie’s (Anthony Hopkins) hair.

“You’re bathed in a rose colored light, my darling,” Cristal coos, and Gemma rushes off to pop in on her frustrated daughter and her more frustrated husband (Josh Brolin) and give them the good news.

Of course, Helena’s husband is leaving her.  Alfie is having the latest mid-life crisis in British history.

“”She already has me dead and buried.”

Daughter Sally is well into her 30s and impatient with her once-promising writer-husband Roy (Josh Brolin) to have a child and get on with their lives, with or without him publishing a new novel.  Roy is frantic to avoid those phrases, “once promising” and “washed up at 38.” But the new book won’t do it for him. Cristal predicts it.

But Roy’s eye strays to the apartment across the way, where a flutist (Freida Pinto) practices and occasionally undresses. Vintage Woody dialogue?

“It’s beautiful, the Boccherini.”

“You know his music? I’m impressed.”

That could lead to something. In Woody World, even boorish lumps like Roy (Brolin totes around an extra 30 pounds) know their classical music and charm svelte Indian artistes with their crude come -. Yeah, he tells her he’s watched her undress. Pinto doesn’t quite play that as a turn on, and without that heat, this affair-to-be makes no sense.

Roy calls her his “muse,” and proceeds to plot his way out of an unhappy marriage and back into writing success.

Sally, meanwhile, is smitten with her handsome gallery-owner boss played by Antonio Banderas, like most in this cast, given nothing to do. Bland “poker partners,” bland college pals, Allen has cluttered this smorgasbord with assorted servings of lukewarm porridge for characters.

Thank heaven Alfie hooks up with a tall, thin hooker, played with ’80s era Woody Allen zest by Lucy Punch. Common,  cheap, and shrill, Charmaine is funny in every scene and Punch makes the most of her every moment on camera. Her presence tips us that maybe Woody intended this to be a comedy. Otherwise, we have no clue.

The writing is old — cobwebbed cliches about tea and palm readers and infidelities and Boccherini.

And when the bland narrator (Zak Orth) informs us that this is “our little tale of sound and fury, signifying nothing,” we aren’t inclined to argue. It’s not easy to call this the worst Woody movie in years, because whatever the charms of “Vicky Cristina Barcelona,” he’s given us a lot of candidates for that prize, movies that should have stayed in the desk.

 Cast: Naomi Watts, Josh Brolin, Anthony Hopkins, Gemma Jones, Freida Pinto, Antonio Banderas, Lucy Punch

Director: Woody Allen

Running time: 1 hour 38 minutes

Industry rating: R for some language.