When I first saw the trailer for A Talent for Murder, I thought Helen Mirren actually was Patricia Highsmith.

Of course, that won’t mean much to most Webb readers, as the late Highsmith remains outside the pale — despite giving us one of the most insanely compelling characters in all of 20th-century fiction.

Featured in 1955’s un-put-down-able Talented Mr. Ripley (plus four sequels), Thomas Phelps Ripley is a mesmerizing sociopath, a chameleon and killer who has now been covered in five different movies — plus a recent Netflix series starring the estimable Andrew Scott.

As you can tell, I’ve been a Highsmith fan for decades — so I was excited to see her latest incarnation in the just-released thriller A Talent for Murder; the talented Miss Mirren stars as the famously misanthropic writer, holed up in her remote Swiss home.

Aldren Ehrenreich plays Edward Ridgeway, a literary agent dispatched to reach the recluse and talk her into penning one final entry in the so-called “Ripliad.”

I’ve read every Highsmith and both major bios, so I already knew how grouchy the author had become in old age; screenwriter Joanna Murray-Smith — who also penned the 2014 stage-play basis for the film — beefs this up, first by telling us that Ridgeway’s predecessor vanished in mysterious circumstances; and second, through repeated suggestions that the author is perfectly capable of physical violence — perhaps even murder — when she dislikes the sort of pressure Ridgeway exerts.

Eventually, Mirren’s Highsmith persuades Ridgeway himself to begin generating her next killer-thriller — at which point, an imaginary story-within-a-story spins off, with somewhat bookish agent smoothly transforming into Ripley himself; he then begins pursuing a pretty and potentially wealthy young woman (played by Olivia Cooke) whom Ridgeway earlier met on the train.

The film cleverly enables us to keep track between the real Ridgeway and his suave, fictional alter ego; yet there’s a notable blurring, as we see that the agent likely had a bit of Ripley lurking inside already. And thus this Talent fittingly invokes the “doubling” theme that obsessed Highsmith in book after book.

Yet the movie never tries too hard. As a thriller, it’s kinda old-school — content to carefully craft its characters, plus a brooding, dread-soaked ambience, rather than staying 18 steps ahead of us, or unspooling nonstop surprises. The ending — which is not so much a surprise as it is, well, an ending — really ties everything together; it leaves you thinking hard about the story, wondering which of the two antagonists contributed more to the outcome.

The film’s chief merits include its two leads, with Mirren equal parts creepy, mysterious, chipper and hateful. As for Ehrenreich: I’ve had my eye on him ever since he scored as a likable cowboy-star in the Coen brothers’ dandy Hail, Caesar!; and this is another career triumph.

The movie also looks terrific — which is not surprising, as it comes from director Anton Corbijn, who despite a slew of music-videos is perhaps best known for those evocative black-and-white U2 album-covers (The Joshua Tree, The Unforgettable Fire — and many more).

Sadly, I was all alone in the theater that day; folks were no doubt preferring the well-reviewed Wildwood and the red-hot You Can See Everything. So Talent will likely leave theaters soon, and you’ll have to wait for streaming.

Meanwhile, you could try the first Ripley book — or even Highsmith’s equally gripping 1950 debut, Strangers on a Train.

That one, of course, is also nicely tied to this film.