How much do you know about “I Know What You Did Last Summer”?

Anyone could be forgiven for not realizing this week’s slasher thriller, starring Jennifer Love Hewitt and Freddie Prinze, Jr., is a brand-new movie, not a revival of the 1997 box-office hit which launched those two as stars and had exactly the same memorable title.

For this “IKWYDLS” is actually the fifth film in a franchise that also includes a one-season Amazon Prime streaming series.

Rising screenwriter Kevin Williamson had in 1996 already scored with his classic thriller “Scream” starring Drew Barrymore. “Scream” spawned a hit franchise and made Williamson, even if he didn’t have an Oscar, Hollywood’s golden guy.

A year later Williamson again hit the bullseye with “IKWYDLS” directed by first-timer Jim Gillespie and a cast that included Sarah Michelle Gellar (who would marry Prinze) and Ryan Phillippe.

The well-reviewed murder mystery had a simple set-up: Four teens from the small North Carolina seaside town of Tower Bay were drunk driving on the 4th of July weekend when they had a hit-and-run accident. Which they tried to cover up by dumping the body.

Only it wasn’t a corpse — yet! Startled to find their victim still alive, they drowned him. Now guilt-ridden killers, they find a year later their lives have all been stunted with early failures.

Then comes that ominous warning note with that infamous title and they find themselves summarily stalked by an unseen hook-wielding maniac.

“IKWYDLS” was a monster hit, making more than $125 million (in ’97 pre-inflation grosses). One year later in 1998 came the (badly reviewed) direct sequel “I Still Know What You Did Last Summer,” again with Hewitt and Prinze. Again, making much money.

As for the series’ murderous maniac? No way would he stay away for too long. He resurfaced in 2006 with the negligible direct-to-video standalone sequel “I’ll Always Know What You Did Last Summer.”

Sony Pictures soon apparently decided that they’d had enough fooling around with variations on that title. Since 2014 the studio has been dutifully developing this new-film, old-title return.

It took more than a decade but here comes a new spin on “IKWYDLS” courtesy of co-writer, co-story by and director Jennifer Kaytin Robinson who begins, naturally, 27 years after the Tower Bay murders of the first film.

And, yes, another hook-wielding malevolent murderer appears, reducing one by one the members of a group of friends one year after they covered up a car accident in which they supposedly killed someone.

Gellar, married to Prinze for 22 years now, has acknowledged they were eager to have her return. But since she was killed off in the original, wouldn’t that be difficult to justify?

“I Know What You Did Last Summer” opens in theaters July 18