LOS ANGELES - "Avengers: Endgame" actress Karen Gillan was in her trailer on the set of "Guardians of the Galaxy" when she heard a knock at the door. Someone was eager to see her intricate makeup as Nebula, an adopted daughter of the intergalactic warlord Thanos.
A mustached smile greeted her. It was Stan Lee.
The legendary writer, who became the guiding force behind the rise of Marvel Comics, gasped at her hours-long, cosmetic transformation into a purple-and-blue space pirate.
The actress was about to film a major fight sequence, she told him as they parted ways.
Lee turned around, clenched his fist close to his face and uttered, "Knock 'em dead."
"That's the coolest thing that's ever happened to me," Gillan shared with The Times at Monday's "Avengers: Endgame" world premiere at the Los Angeles Convention Center.
Lee, who died in November at age 95, was on the minds of several stars and filmmakers attending the film's first public screening in a custom-built 2,000-seat theater with a 70-foot screen.
Anthony and Joe Russo's movie features Lee's final film cameo, marking the end of an era after 11 years of surprise appearances throughout the Marvel Cinematic Universe. To commemorate the moment, the studio will release a behind-the-scenes video of the iconic cameos.
Benedict Wong, who plays Doctor Strange's sidekick Wong, described the event as bittersweet. "As much as it's a real joyous moment, it's obviously tinged with sadness," said the actor, who met Lee a few times. His favorite was the first time they met, at 2016's "Doctor Strange" premiere.
"I just made a bee-line over to him and sort of fanboyed him," Wong recalled. "I just said, 'Stan you don't know me -' and he immediately interrupted and said, 'You're Wong. You're great!' And it was a big welling-up moment."
The actor wished he'd been among the dozens who came to the "Endgame" set to watch Lee perform his surprise scene.
Executive producer Trinh Tran laughed as she remembered it. "People you normally wouldn't even see on the set showed up, and you're like, 'Where did all these hundreds of people come from?'
"He has that impact on all of us. Not just the fans, like the crew are his fans. We love him. We wouldn't be here without him," she said.
Co-writer Christopher Markus put it this way: "It was like Santa came to set."
Markus was "a little worried" that moviegoers would think the cameo was developed after Lee's passing, though it was invented and shot prior to that - even before Lee's appearance in the March release of "Captain Marvel."
"This is a unique cameo, and he was so in it," writer Stephen McFeely chimed in. "He went for it. It was fantastic." As he spoke, cries from cosplayers dressed as some of Lee's characters were heard through the convention center doors.
"You know, you don't give Stan Lee a page of dialogue," McFeely said. "You give him one full thing where he can shine."
When the movie opens Friday, look out for Lee in a driving scene, said second unit director Sam Hargrave, who shot the sequence with Lee and a stunt double.
"It was one of the most beautiful cinematic experiences I've had in the Marvel universe," Hargrave remembered. "He is Marvel. Without him, I'm not standing here."
"Endgame" picks up where 2018's "Avengers: Infinity War" left off. After acquiring six Infinity Stones and the powers that come with them, super-villain Thanos (Josh Brolin) appears to have killed half the universe's population with a simple snap of his fingers.
Chris Hemsworth and Paul Rudd, whose characters survived the snap, joined in on the collective nostalgia Monday.
"I just remember the sort of childlike wonder of that guy and the love for these stories," Hemsworth said of Lee.
Rudd recalled hanging out with him on the set of 2015's "Ant-Man," when Lee expressed his excitement to see Scott Lang on the big screen.
"He was going to finally see the scale of it as he always imagined," Rudd said. "That was really thrilling."
But perhaps actor Hiroyuki Sanada, who makes a surprise appearance of his own with a fight sequence filmed in one take, said it best: He was not able to see Lee on set, but had hoped to see him at the premiere.
"It's so sad," he said, shaking his head. "But I believe he's here tonight. I believe."
This article is written by Christina Schoellkopf from The Los Angeles Times and was legally licensed via the Tribune Content Agency through the NewsCred publisher network. Please direct all licensing questions to email@example.com.