Preview: Phantom Limb's 69S.

A puppet company ventures into the frozen wastes of Antarctica.

Photograph: Sarah Walker

"You go to Antarctica because you can't go to outer space," says Jessica Grindstaff, who with her husband and artistic partner, Erik Sanko, traveled to the south pole early last year on a National Science Foundation grant for artists and writers. "I think we're the first puppeteers to take advantage of that grant," says Sanko, a little sheepishly.

Unlikely ventures are this couple's stock-in-trade. Their company, Phantom Limb, bowed in 2006 with The Fortune Teller, which set Sanko's spindly, lovably macabre marionettes against the backdrop of Grindstaff's painstaking designs. With the brand-new 69S. at BAM, Phantom Limb has stepped up its game with an outside director (Sophie Hunter), music cowritten by Sanko and the Kronos Quartet's David Harrington, video projections by Shaun Irons and Lauren Petty, and dance courtesy of Gallim's Andrea Miller. Did we mention the stilt walkers?

It's an ambitious show about an audacious journey: the 1914--17 trek of Sir Ernest Shackleton and his men to map Antarctica from sea to freezing sea. The title refers to the latitude at which Shackleton's ship was swallowed by a crevasse and crushed. Memorably quoth he: "What the ice takes, the ice keeps."

The longing for terra incognita expressed by Grindstaff isn't so different from the itch that drove explorers like Shackleton. "There was a kind of worldwide mania then to master the last uncharted continent," says Sanko. "It is a heroic landscape."

"There's a magnetic and emotional pull you can feel when you're there," the designer adds. "It feels like it's living and breathing, which is kind of ironic, because it's not." The vistas are likewise disorienting, she says: "There are times you have no idea what you're looking at—what is ice, snow, sky, sea, frozen atmosphere or fog. And there's no point of reference for scale, because there's nothing that grows or was built."

This otherworldy vision inspired Grindstaff to create a look more abstract than representational. "I didn't think it was worth trying to re-create it with Styrofoam," she explains. "We took a more sculptural approach. So I started to think of icebergs as three-dimensional topographical maps." The result, Sanko says, resembles "Noguchi lamps shaped like icebergs."

What's striking about Shackleton's story is the way it reversed its era's expectations of heroism: Unlike his predecessor, Captain Robert Scott, who reached the south pole but perished in the effort, Shackleton scrapped his continent-mapping mission when disaster struck and made his new directive simply to save the lives of his crew. There's a reason Scott was lionized in his time, while Shackleton has become a latter-day saint.

"With Scott, it was clear they would get to the pole but wouldn't survive—and they just kept making those decisions," Grindstaff marvels. "With Shackleton, on his first expedition, he got within 100 miles of the Pole, but he calculated what would happen if they went and came back; he knew that not all of them would survive, so he chose not to do that. That was not the kind of decision people were making then."

A tale of tough choices required for survival naturally resonates in an age when icebergs themselves are endangered. "The question is: What kinds of decisions are we making now?" Grindstaff wonders. "Our planet is falling apart, and it seems like half of us are looking at that as a major crisis, and we need to reassess how we've been living our lives. And the other half are just moving ahead."

Discerning this message in 69S. may be as difficult as parsing the Antarctican horizon. "It's kind of a weird show," Grindstaff confides, almost apologetically. "People are going to be surprised. You're not going to see a puppet show about Shackleton. I mean, you are—it is about Shackleton, and there are puppets. But it's much more degraded than that."

Degraded? "I keep talking about it as if we wrote the story on carbon-copy paper," she explains, "and it's a stack that's 25 deep, and you're looking at the last generation." Sanko chimes in: "It's a story you put in your pocket, and then washed your pants 30 times."

69S is at the BAM Harvey Theater Nov 2--5.

See more in Theater