PHOTOS BY SEAN COLLIER

On a clear December morning, two world-class ice skaters took to the ice in PPG Plaza.

While the popular rink is known for hosting families and joyful holiday visitors, it’s not usually the spot for stunning feats of athletic grace. On the morning of Dec. 4, however, a pair of performers from Cirque du Soleil’s ice spectacular “Crystal” put on a show for passersby, soaring and turning around the towering Christmas tree.

“I love the set, and the scenery,” says Hjordis Lee. “It’s perfect.”

Lee and Michael Helgren, her partner that morning, are part of the troupe of performers currently touring the world with “Crystal,” the first and thus far only on-ice show from the long-running circus. “Crystal” is set to return to Pittsburgh from Jan. 18-21 at PPG Paints Arena. The show follows a teenage girl, Crystal — played by Lee — as she explores her own imagination.

“With Crystal being a teenage girl who has a breakthrough experience and sees her life in a different way — and really grows up through that experience — I think that’ll speak to a lot of people,” says Crystal Manich, the artistic director of “Crystal.” (Yes, she’s named Crystal and is directing “Crystal,” a show about a character named Crystal.)

Manich is a Pittsburgh native with degrees in drama and arts management from Carnegie Mellon University; a director of opera and theatrical productions all over the world; now, she is bringing a Cirque du Soleil show to her hometown.

“Cirque du Soleil is known for innovation — and what’s perfect about this show is that you’re mixing two very different mediums, mixing acrobatics with skating. I think that the combination is really a culmination of what I’ve done in my career.”

Cirque du Soleil has gotten in the habit of making a January stop in Pittsburgh, including recent visits from the elegant touring show “Corteo” and the vibrant, boisterous “Ovo.” Even among the company’s cabinet of curiosities, “Crystal” is unique; in addition to its innovative blend of disciplines, it is one of the only Cirque du Soleil productions to incorporate popular music, with key moments choreographed to songs by Sia and Nina Simone.

“They’re different arrangements and different artists, but they really do add to the emotionality of Crystal’s story,” Manich says.

“It’s the one and only Cirque du Soleil show that figure skaters can be a part of,” says Helgren. “It’s kind of a dream come true, but also something that we never thought could happen, being a figure skater … Cirque du Soleil opened up a whole different door for us to explore.”

While the unique aspects of “Crystal” make it a tantalizing ticket for Cirque du Soleil devotees, Lee says it will also serve as a fine introduction to the company’s work for beginners.

“It’s a story that everybody can relate to … it’s a relatively simple story, but deep — and I think having that connection with every single audience member makes it very unique and special.”

Seven performances of “Crystal” are scheduled for the Pittsburgh stop, including two matinees on Saturday, Jan. 20, and another matinee on Sunday, Jan. 21.