Cheap Trick was back home, playing a concert in 1979 at the fairgrounds outside of Rockford. Brenda McMahon, 18, was there with friends. She bumped into Mick Levine, 19, who was working as a stage hand. They knew each other from their not-so-long-ago days at Oak Park and River Forest High School. "I confessed I'd been crazy about her since high school," Levine said. "And she was a little tipsy and said she was attracted to me. And I pretty much wanted to drop to my knees and thank the stars above."He whisked her from the show to go thrift shopping at the Salvation Army."We saw a really great leopardskin lamp, and it turned out we were into a lot of the same music and kitschy things," Levine said. "We were both Cramps fans and into pyschobilly and punk rock, which back then were dirty secrets to the world, but the underground scene was wonderful. From that point on, we were pretty inseparable."In 1982, deciding college wasn't for them, the pair opened a vintage clothing shop named Radio inside the Metro music venue at 3740 N. Clark St. near Wrigley Field. The place, which had vintage radios everywhere and was open nightclub hours — around 8 p.m. to 4 a.m. — became a gathering place for punks rockers and the rockabilly crowd."We were both little punk rockers who really were enamored with fashion," Levine said. "She was the workhorse who kept it together, and I was, like, Mr. Social Butterfly Jabbermouth."They closed the store after a few years because of problems with their lease and opened a new shop in the late 1980s at 3406 N. Halsted St. called Ninety Ninth Floor, offering an eclectic selection that included vintage sharkskin suits, chainmail bikinis, Doc Martens boots, motorcycle boots, body-piercing jewelry, stiletto pumps, corsets, Jughead hats, latex dresses and other fetish wear."It was the kind of stuff most places would be scared to touch," Levine said.The couple drew devoted shoppers from a broad cross-section of Chicago, from sheepish cross-dressers to punks and club kids as well as a few famous people, among them Jimmy Page and Robert Plant of Led Zeppelin, Slash from Guns N' Roses and the Bulls' Dennis Rodman.At first, the couple lived in a space behind the store before moving to an apartment above it. It's where Ms. McMahon died Oct. 11 from complications from multiple sclerosis. She was 63. Brenda McMahon.Provided "She was softspoken, very empathetic," Levine said. "There wasn't a creature she wouldn't take in and take care of. And she was not judgmental. She was very welcoming, not overly chatty like me, just very gracious and very humble. But she was not a creampuff. If she had to be a scrapper, she could be. But she always said, 'Choose your battles wisely.' "One such occasion came while waiting in line to see her favorite band, the Cramps. A woman cut in front of her. A fight ensued.Lux Interior and Poison Ivy, the husband-wife duo at the core of the Cramps, once shopped at the couple's store. Interior bought knee-high latex Bettie Page boots. Ivy bought shorts with flames stitched onto the crotch that fanned out to the hip. Ninety Ninth Floor, the business Brenda McMahon ran on Halsted Street with Mick Levine.Provided Ms. McMahon's style tilted Goth, while Levine leaned to what he called "gravedigger chic." She delighted in a suitcase full of black clothes she found for sale on Maxwell Street from a vendor who told her his Italian grandmother had worn the clothing while in mourning.Ms. McMahon and Levine didn't believe in marriage but appreciated the protections it offered, so they had a no-frills City Hall wedding in 2004.Their store became a second home of sorts for Julia Garsenstein when she was a teenager who'd left home."Brenda and Micky looked out for me," said Garsenstein, who later worked at the store. "I was like a surrogate family member."The store closed in 2015, and the couple shifted business online, including selling on Etsy under the name Atomicfireball.Ms. McMahon was born in 1961 in La Rochelle, France, to Beatrix O'Donnell and Tom McMahon. Her father was in the military at the time. When the family later settled in Oak Park, he worked as a tradesman, and she was a caregiver for seniors."Brenda was kind and beautiful, and it was meant to be," Levine said. "Mundane, monotonous things were a joy as long as it was with her. To hear her laugh and tell me she loved me — the most wonderful things I ever heard."A memorial service is in the works.