Elvis went to a Hollywood Halloween party in a mask. Across the room stood another Elvis, and he was one of the biggest singers in America.

Sixty-nine years ago tomorrow night, Elvis spent Halloween at a Hollywood party with a mask over his face.

It was Oct. 31, 1957. Elvis was in Los Angeles that week for his first concerts there, two nights at the Pan-Pacific Auditorium on Oct. 28 and 29. And when Halloween came around, he had an invitation to a big Hollywood party.

To get a feel for Elvis in Hollywood that year, this short film goes behind the scenes of “Jailhouse Rock,” the movie he made there in 1957.

Behind the scenes of Elvis’s 1957 movie “Jailhouse Rock”

The host was Sy Devore, a tailor to the stars. Devore opened his shop at Sunset and Vine in 1944, and his customers included Bing Crosby and Nat King Cole. Elvis shopped there too. According to Devore’s niece, he bought suits right off the rack, as many as 20 at a time.

The party was held at a Los Angeles restaurant. An auction listing for a set of old photos from that night names it as Lucy’s.

Elvis’s old friend George Klein was there with him. Klein was a Memphis radio DJ who had known Elvis since their days at Humes High School, and years later he told the story in his memoir, “Elvis: My Best Man.”

“The party was pretty amazing, even by Hollywood standards,” Klein later recalled.

Plenty of the guests came in costume. A 1957 contact sheet from the party shows bandleader Harry James in a baseball uniform. Elvis wore a mask. That’s all anyone has ever said about his costume, though Klein gave one small hint when he called him “Mardi Gras Elvis.”

And somewhere in the crowd, a guest had come dressed as Elvis Presley.

It was Nat King Cole.

If you were around in the 1950s, you know that warm, velvet voice. Cole sang “The Christmas Song” and “Mona Lisa,” the No. 1 song of 1950. In 1956, “The Nat ‘King’ Cole Show” debuted on NBC, the first nationally broadcast TV show hosted by a Black American.

So here was one of the smoothest singers in the country, dressed up as rock ‘n’ roll’s wild new kid.

“Nat King Cole was dressed as Elvis, with a black leather jacket, pasted-on sideburns, and a guitar around his neck,” Klein remembered. The photo contact sheet backs him up. It lists “Nat King Cole dressed as Elvis Presley, complete with guitar.”

Klein got talking with Cole first. “He was extremely nice, and when he heard I was with Elvis, he said he really wanted to meet him,” Klein wrote.

Then Klein went and found Elvis.

“But as soon as I told him who Nat King Cole was dressed as, he had me lead him there.”

Nobody wrote down what the two men said to each other. Klein never forgot the scene, though.

“I’ll never forget the sight of Mardi Gras Elvis standing there talking to Nat King Cole Presley.”

That wasn’t the only surprise behind a costume that night. Klein noticed a “very cute little clown” at the party, and he had no clue who she was “until Cliff pointed out that the little clown was Debbie Reynolds.” Cliff was a friend in Elvis’s group, and Reynolds was the star of “Singin’ in the Rain.”

The party itself lives on in photos from that night, including one of Elvis in his mask. They’re the closest we’ll ever get to seeing the real Elvis meet the other one.