For most of its 20-year history, Pig Iron Theatre Company has remained stubbornly inventive, creating physically imaginative and sonically adventurous new work or offering surprisingly skewed perspectives on existing plays. So the company can be forgiven for using the occasion of their 20th anniversary to take a rare jaunt down memory lane.

“We tend to try to look mostly forward,” says co-artistic director Quinn Bauriedel. “But it’s a good moment to take stock of the crazy 20-year journey of the company. We’ve managed to achieve some things that I don’t think anyone could have foreseen when we started.”

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To mark the occasion, Pig Iron is reprising one of its most popular works after a full decade in hibernation. “Gentleman Volunteers” is an epic World War I-set melodrama told in decidedly non-epic fashion, with no set or costume changes, a few bare light bulbs, live sound effects and four actors. It was originally produced in the basement of St. Mary’s Church on the Penn campus, and has since traveled the world.

“We quickly realized that it was special because it’s so intimate,” Bauriedel recalls. “It’s as simple a project as theater could be, but it takes the audience somewhere far away. It harkens back to our simple, humble roots, when we had no budget and were working with the simplest of costumes and sound effects, but we created something that put Pig Iron on certain artistic maps.”

Premiered in 1998, “Gentleman Volunteers” became suddenly, tragically relevant when the country found itself on war footing once again. The current production also coincides with the 100th anniversary of World War I, so the play offers a chance to reexamine the “war to end all wars” against the backdrop of another century’s worth of conflict around the world. At one point, Bauriedel remembers, Pig Iron performed a run of the show at the Drexel Armory as soldiers were returning home from Iraq. “Their first stop was the Armory, so we were confronting them in the dressing room while they were dumping sand out of their boots. That resonance was really potent, and it feels like it’s important to continue to tell that story.”

Casting

The majority of the current production will feature a new cast trained in Pig Iron’s unique theatrical language, but the original cast — including Bauriedel, Dito van Reigersberg (perhaps better know in Philly as his alter ego, drag queen Martha Graham Cracker), and sound designer James Sugg — will return for two benefit performances in another atypical bout of poignant nostalgia.

“It was a really special show,” Bauriedel says. “It was kind of a play about who we might have been a hundred years before: idealists having an adventure and seeing the world for the first time.”

If you go:

"Gentleman Volunteers"

Dec. 10-27

Christ Church Neighborhood House

20 N. American St.

$20-$30

www.pigiron.org