For a blind date, we could hardly do better than Helen Mirren and Ian McKellen.

They are brought swiftly together by a computer dating service in the opening minutes of "The Good Liar." Both click "widowed." When they cautiously sit down in a quiet London restaurant, and Mirren begins sipping a martini, it's hard not think they're a match made in heaven.

And yet "The Good Liar," a modest middlebrow thriller, never lives up to the sheer pleasure of seeing its two leads together, for the first time as co-stars. Directed by Bill Condon ("Kinsey," "Beauty and the Beast," "Dreamgirls") and adapted from Nicholas Searle's 2016 novel, "The Good Liar" has the polish that you would expect from all involved, but little of the sparkle.

Immediately, there's a play between truth and deceit. When Roy Courtnay (McKellen) is filling out his dating profile, he selects "non-smoker" while a cigarette smolders nearby. Right after their meeting, Roy — once out of eyeshot from Mirren's Betty McLeish — quickly sheds his kindly old gentleman persona and skips into a nightclub to hash out a scheme with his co-conspirators over champagne.

What unfolds goes considerably further than the small exaggerations and distortions commonly found on Tinder pages. "The Good Liar" delves into deeper falsehoods of identity and history, teasing out a twisty narrative that winds its way back to World War II. It aspires to the psychological intrigue of Patricia Highsmith or John Le Carre without ever summoning such a thick air of mystery and danger.

Roy is a conman. He's got a few hustles going on, but his focus is drawn increasingly to getting close to Betty and robbing her of her small fortune, one amassed from a career as a history professor at Oxford. She lives outside London, and Roy's quick insertion into her life (he feigns a bad limp to score a bed in her guest room) raises the suspicions of Betty's grandson, Steven (Russell Tovey).

It would give too much away to discuss the film's big reveal, but there also isn't a great deal worth discussing aside from that. For one, we can see a major turn coming all along in the script by Jeffrey Hatcher (who previously teamed with Condon and McKellen for "Mr. Holmes"). Mirren is far too cunning an actress to simply play a suckered old lady in the suburbs. We know it's just a matter of time until her intelligence and ferocity reveal itself.

In the meantime, there are a few things to chew on, mainly the stirring score by the great Carter Burwell ("Carol," "No Country for Old Men") and the undeniable talents of Mirren and McKellen, who stitch the film together through subtle, skillful glances and gestures. They're artists at play, clearly enjoying each other's company.

"The Good Liar" is a kind of film one wants to love. Such old-fashioned genre movies, let alone those starring actors in their 70s and 80s, are hard to find these days. But in trying to take a simple crime set-up and stretch it into a more sweeping tale of vengeance and victimhood, "The Good Liar" has to make some fairly preposterous moves to get there, and it doesn't do a very good job of cloaking them.

If you're in the mood for a Hitchcockian thriller rooted in the crimes of Nazi Germany, hunt instead for Christian Petzold's underseen "Phoenix." Now that film will flatten you.

"The Good Liar," a Warner Bros. release, is rated R by the Motion Picture Association of America for some strong violence, and for language and brief nudity. Running time: 110 minutes. Two and a half stars out of four.