EVERETT — During the day, Everett librarian Kate Mossman is the consummate professional, all buttoned-up blouses and tailored slacks.

But at night, out comes the black T-shirt and spandex shorts, the pads, the helmet and the mouth guard.

Everett Public Library’s assistant director is

a speed demon on eight wheels, the captain of a local roller derby team called the Camaro Harem.

“I get an intrinsic reward for the sheer athleticism involved and pushing myself to the limit,” Mossman said.

She’s known at the rink as “unshine.” On her orange jersey is the Dewey Decimal number for solar eclipse: 523.78. Now in her fourth season, she’s a respected skater experienced and talented enough to handle any position on the track.

Her teammates say she’s driven, a leader and one of the fastest skaters in the Jet City Rollergirls league. She’s known for a wry sense of humor and her habit of wearing temporary tattoos in odd places — like the time she pasted a red heart tattoo reading “I love libraries” on her neck.

“She’s fast, accurate, a hard hitter,” said teammate Candi Edwards, a nurse also known as Greta Gurney. “She brings out the best in us.”

Roller derby is a sport with a healthy amount of cleavage, powerful thighs and tattoos. It draws a loyal following in the Northwest, big enough to fill Key Arena in Seattle and sell out college gymnasiums in this county.

Five skaters circle around a track. Each team has a jammer who tries to get through a pack of blockers and score as many points as possible.

The sport requires speed, agility and endurance. It can be as rough as rugby, with skaters sometimes sustaining gruesome injuries: broken bones, hematomas and torn tendons.

Mossman joined four years ago when the sport was still relatively young here. She saw the Jet City Rollergirls skate by during a Fourth of July parade. Among the politicians and the auto dealers, they were — as she remembers it — “the coolest thing in the parade.”

Mossman and her husband, Grant, had just moved to town, and she needed a way to get involved in the community. Some people might think about Rotary or the Chamber of Commerce. She found herself dreaming up derby names and showing up at the Everett Skate Deck.

“This is not Rotary,” she said. “I can hang with the Rotary crowd if I need to.”

With no serious skating experience, Mossman was amazed when she tried out and got picked for the league. At first, she was like Bambi on skates. She took classes and she practiced.

Coach Mich Congdon, a former hockey player, said Mossman quickly improved. She brings smarts and smoking speed to the track. She’s known for a fierce, focused aggression.

“When I first watched her skate, I was certain she had skated before,” he said.

Mossman spends her time at work focused on supervising librarians and working shifts at the adult reference desk. She’s neat and organized, and she doesn’t talk about her personal life at work, said library director Eileen Simmons.

Still, her boss said Mossman has developed a “flock of derby followers” at the library.

“Quite a few people follow the team,” Simmons said

The library director said she’s even attended a few bouts, although she’s not much of a sports fan.

“She’s really good,” Simmons said. “I saw her early on and then I went the following season and I was amazed at how much more aggressive and skillful she had become.”

Mossman, who didn’t want to divulge her age, isn’t sure how long she’ll be a derby girl. So far, she’s jammed her thumb, herniated a disc in her back, gotten a concussion and tore a ligament in her knee.

Something about the thrill of out-juking a great blocker, the adrenaline rush, the pride of winning — it keeps her lacing up her skates.

“I’ll go until I know it’s time to stop,” she said. “I don’t think it’s quite time yet.”

Reporter Debra Smith: 425-339-3197 or dsmith@heraldnet.com

Roller derby

Watch Kate Mossman and her team, the Camaro Harem, in action at 6 p.m. April 9 at the Everett Community College gymnasium. Bout 1 is the Hula Honeys vs. CarnEvil, and bout 2 is Camaro Harem vs. the Pink Pistols.