Fans are in a frenzy, as heavy metal royalty has arrived in Denver. Metallica is in town for the band's M72 World Tour. It features two shows Friday and Sunday at Empower Field at Mile High. 

Ahead of those concerts Thursday morning, crowds flocked to Sports Castle along Broadway for a pop-up shop, with lines winding around the building and down the street. 

Meanwhile, super fans David Rowe and Brian Zappanti stood in the stadium parking lot. They're ecstatic to see their favorite band this weekend.

"Nothing like getting off work after a hard day and cranking up some 'Master of Puppets' on the way home," Zappanti said.

"And Lars [Ulrich] beating up the drums nonstop and relentless," Rowe added.

The pair proudly clutched a homemade banner. "I almost feel like it's a piece of Metallica history," Rowe said. Their love for the band is written all over the large piece of artwork. It tells a story on its own that started back in 1988.

"I acquired a bedsheet and some markers and put it on the basement wall at my parents' house, and we worked on it slowly over a couple of months. We used a lot of markers," Zappanti laughed. "That's what was cool about the late '80s though. People were just super into music."

Naturally, when Zappanti and Rowe trekked up to Denver from Trinidad, Colorado to see Metallica on tour, they brought the banner with them. It was a highly-anticipated show in what was then simply called "Mile High Stadium."

They remember the night vividly.

"We watched the Metallica set. I looked over at Brian at the end, and I said, 'Let's go.' And he said, 'What? What are you talking about?' And I said, 'Let's go get the banner.' We're going to meet Metallica. We left the stadium knowing we weren't going to get back in," Rowe recalled. "We went out to the car, walked around to the back, and they happened to be taking pictures with their tour photographer. We raise the banner, and we're screaming, and they motion us down. They sent down a roadie, he took (the banner) with a camera got some pictures. At that point, we are happy as can be."

Then, something out of their wildest dreams happened. "The next morning, we go to the Embassy Suites to try to officially meet Metallica and say we were the guys with the banner. Slowly one by one, they started coming down. We were able to get some pictures with them."

Those photos are so treasured, Zappanti regularly keeps them in a safe. Ans, now, reminiscing on those memories at Mile High in the same exact spot where the band took a picture with their banner, the super fans say it's surreal. 

"I had a lot of hair," Rowe said with a smile.

Their reunion with the band, they say, is hopefully ahead. They'd love to see and hang out with Metallica again while they are in town.  

"It's a little emotional being back. It's something that we dreamt about and hoped for," Zappanti said.