Perhaps the greatest delight of the new teaser for Quentin Tarantino’s ninth film, “Once Upon a Time in Hollywood,” is the unexpected prominence of Bruce Lee. Lee, played by Mike Moh, demonstrates his kung-fu mastery with stuntman Cliff Booth, played by Brad Pitt.

He’s onscreen for about 15 seconds of the one-minute-forty-five-second trailer, but they’re electrifying. Why is Lee there? Partly, of course, because Tarantino adores him. But this isn’t a case of a director shoehorning someone into a story. Lee played a small but significant — and very bizarre — part in the story of the Manson killings.

There’s no telling how much of that story will be in Tarantino’s film. And if you don’t want to know the details, we’d recommend you stop reading now.

Also Read: Why Bruce Lee's 'Once Upon a Time in Hollywood' Costume Is an Intriguing Surprise

Because once upon a time in Hollywood, believe it or not, a young director named Roman Polanski briefly believed Lee had committed the Manson murders himself.

Matthew Polly, author of the excellent “Bruce Lee: A Life,” spelled out the connection for us last summer in an episode of the “Shoot This Now” podcast, which you can listen to on Apple and right here.

In 1965, Lee met Jay Sebring, who would later provide some of the inspiration for Warren Beatty’s character in “Shampoo.” At the time, Sebring was dating Sharon Tate, who is played by Margot Robbie in “Once Upon a Time in Hollywood.”

Also Read: Quentin Tarantino Finds His Bruce Lee for 'Once Upon a Time in Hollywood': How Mike Moh Honored Lee

Lee soon found himself in frustrating sidekick roles (see: “The Green Hornet”), staging fights for Hollywood films, and trying to break into leading-man parts that were usually denied to non-white actors. He also became what Polly calls a “sifu to the stars” who trained actors like Steve McQueen in the martial arts.

In the summer of 1968, the movie “The Wrecking Crew” paid Lee $11,000 to teach Tate and other actresses how to fight. By that time, Tate had married Polanski. As Polly writes, she invited Lee to dinner, telling Polanski, “The two of you will get along like a house on fire.”

Soon, Polanski was one of Lee’s regular martial-arts clients. They became so close that Polanski invited Lee to his ski chalet in Gstaad, Switzerland, and it was on that trip that Lee bought the yellow suit he wore to fight Kareem Abdul Jabbar in “Game of Death.” Decades later, Uma Thurman’s Beatrix Kiddo would wear an almost identical suit to battle the Crazy 88, Gogo Yubari and O-Ren in Tarantino’s “Kill Bill Vol. 1.”

On Aug. 9, 1969, Tate and Sebring died at the hands of the Manson Family at her and Polanski’s home on Cielo Drive. So did Tate’s unborn baby, aspiring screenwriter Wojciech Frykowski, and Abigail Folger, heiress to the Folgers coffee fortune, and 18-year-old visitor Steven Parent.

In a bizarre turn of events, before the true killings were known, Polanski briefly suspected Lee of the murders. The killer or killers and left a pair of glasses at the home on Cielo Drive, and one morning after the murders, Lee casually mentioned to Polanski, “I’ve lost my glasses.”

Polly explains what happened next at the 15-minute mark of the podcast. It involves what must have been a very tense trip to an optician’s office, in which Polanski weighed the possibility that Lee had murdered his wife and their friends. As Polly writes:

Polanski’s heart raced. Bruce was part of the circle of friends, but he was also, as the only Asian, an outsider looking in. He knew how to use a gun and was an expert in bladed weapons. He had the strength and skill to overpower multiple victims. Perhaps Sebring had invited him over and something had gone terribly wrong. Perhaps he was secretly in love with Tate and had snapped.

To be clear: Polanski was wrong. And it’s unclear how much of this will be in “Once Upon a Time in Hollywood.” But the inclusion of the Bruce Lee so prominently in the teaser trailer is thrilling.

First, it allows Tarantino to honor one of his film heroes. (Even if he is kind of the butt of a Booth’s joke about manslaughter.) Second, it tells us that the film, as promised all along, will offer a spectacularly different take on the Manson murders than we’ve seen before. (As if Tarantino ever tells a straight story.)

And finally, because Mike Moh looks like he’ll be a great Bruce Lee. We aren’t surprised since the actor has made no secret of his love and respect for Lee.

If you found the details above interesting, we strongly recommended listening to our entire interview with “Bruce Lee: A Life” author Matthew Polly and reading his book. It’s outstanding.