From left, Andrew Cockburn, Colin Davies and Ken Shoemaker perform during a dress rehearsal for the play “Galileo's Torch” at John Henry's farm in Flint Hill, Va., on June 5. (Evelyn Hockstein/For The Washington Post)

It looks like neo-Druidry: cloaked men stepping purposefully up and over giant rock formations as the pre-solstice sun drops on Thursday evening. But that’s former Reagan Department of Justice official Bruce Fein high on a promontory pulling a white cowl up over his head. And there’s conservative commentator Richard Viguerie opposite, clad from head to toe in cardinal red. They’re arguing — and, oh dear, so high up! — while way below, in black and gold, British writer Andrew Cockburn watches in concern.

They’re acting, of course — and not the prescribed roles they play in Washington’s public life. No, this band of Republicans and Democrats, conservatives and liberals are Rappahannock County friends, with a bond rooted in regular Sunday morning meetings on a local country store’s porch. Now they are combining forces to stage local author James Reston Jr.’s new play, “Galileo’s Torch.”

Strange and wonderful things can happen, you begin to understand, when you take Washingtonians out of Washington.

Reston’s work replays the 17th-century trial of Galileo Galilei — a compelling tale of what happened when the astronomer-mathematician violated Catholic dogma by asserting that the Earth orbits the sun. Galileo was summoned before the Inquisition, put on trial and threatened with torture in a clash of science and religion that still resonates today.

Who could resist being part of the first public performance in this vast outdoor theater, excavated out of a granite hillside by a genial and eccentric businessman named John B. Henry, who’s famous for high-voltage Halloween spectacles?

“This is a very unusual group of people who would never come together in Washington,” explains David Tatel, a judge on the federal appeals court in the District. “We are all so different, from such different groups. And Washington is a pretty segregated place.”

This Saturday, Tatel, a Clinton appointee, will make his theatrical debut alongside Bush 41’s White House counsel C. Boyden Gray (playing Pope Urban VIII). But the play’s most striking partnership — or juxtaposition — is of modern conservatism’s “funding father,” Viguerie, in the role of Cardinal Bellarmine, and the man playing his adviser, Bob Kozak, who’s bent on making biofuels from bits of carrot and who ran for Congress in Maryland as the Green party candidate.

There will be seating for 150. But many more may come with picnic blankets and folding chairs, drawn by the eccentricity of the event, with a set built by a master of epic murals and mezzotint, Craig McPherson, and music chosen by Col. John R. Bourgeois, former conductor of the U.S. Marine Band.

Thursday’s dress rehearsal is at Stone Hill farm, some 65 miles west of Washington. Henry — one of the Patrick “Give-me-liberty-or-give-me-death” Henrys — bought the 18-acre property a decade ago and set about re-sculpting nature. Think Capability Brown with a touch of caveman chic. A 30-ton “Neolithic” mailbox marks the entrance. On his fields, with views of the Blue Ridge Mountains, Henry has built huge, dry stone walls and embedded sheepfolds in them; a hillside tomb to hide the pool pump; and a stone circle. That’s right, a virgin-sacrificing sort of circle.

Henry goes great distances to find the perfect stone. “For the big guys, you’ve got to go to glaciers,” he says, referring to the boulders he shipped in on 40-foot trucks from Canada. But others were quarried right here, and when the work was done the space created an amphitheater.

What Henry needed was a play to be performed there.

A few months ago, Henry was driving along Route 66 between Rappahannock and Washington, listening to a 1994 biography Reston wrote of Galileo at three times normal speed (a trick he had learned from Tatel, who is blind and consumes books at five times normal speed). Henry reached the chapter about the trial. He listened, was stunned, pulled over and made a call.

“This is the most dramatic thing you’ve ever written,” he told Reston. As a play, it would be the perfect way to inaugurate his amphitheater.

Days later, Sunday morning talk on the porch of the Laurel Mills Store turned to staging Reston’s play in Henry’s amphitheater, and Tatel spoke up:

“I want to be the Grand Inquisitor,” the federal judge said.

If the amphitheater provided the location, and the porch became the planning HQ, the nonpartisan spirit of the event (and many of its actors) stems also from a speakers group, founded in 2003 in the wake of the invasion of Iraq.

Washington’s segregation — particularly its political segregation — turns out to be a hobbyhorse of Henry’s; reining it in, a pet cause. In response to what they saw as the imperialism of neocons, he and Gray helped launch the Committee for the Republic, a group dedicated to reviving America’s founding ideals, such as leading by example rather than by force. The committee hosts monthly “salons,” bringing in speakers and challenging the audience to grapple with difficult — and divisive — ideas.

There are no more difficult and divisive ideas than those in Reston’s play — about science, faith and torture. The process of preparing a “staged reading” — costumed but with scripts in hand — has resembled a series of salons, an opportunity to debate the message of the play even as Reston refined his work. He created a new part for Fein — the ghost of Giordanno Bruno, who was burned for heresy, and which promises, Reston says, to be “one of the great moments of the evening.”

The ad-hoc company met in April, at Gray’s Italianate Georgetown mansion, surrounded by Whistler etchings and 18th-century oils of the Grand Canal in Venice. (“Galileo’s big mistake was to leave Venice,” Gray points out.) Talk turned to the play’s contemporary relevance, to stem cells and SETI, and of who might be a modern Galileo.

In May, the cast assembled in Tatel’s courtroom, where the Grand Inquisitor, in black cloak and tall hat, interrogated the hapless Galileo below the seal of the U.S. Court of Appeals for the D.C. Circuit.

“The word ‘unique’ is overused,” says Rick Davis, executive director of the Hylton Performing Arts Center in Manassas who agreed (for “a little professional courtesy”) to direct the play. But he has never worked with a troupe like this. He’s making actors out of public speakers, blending the inexperienced with the one true pro, Colin Davies, who plays Galileo and boasts “a very loud voice.”

“It’s such an amazing spectrum of folks,” the director says. He’s not talking about the color spectrum: The actors’ range from too-many-hours-in-the-office pale to a man-of-means tan. Nor the gender spectrum: The only woman with an acting role is Edie Tatel, the judge’s wife, who plays the Grand Inquisitor’s scribe.

Davis is referring to their range of viewpoints — the Viguerie-Kozak spectrum, which is a source of genial banter at the amphitheater, while the actors wait to start their dress rehearsal. You can take the Washingtonians out of Washington, but you can’t take Washington entirely out of the Washingtonians.

Here’s Cockburn, Davies and now Fein, delayed on Thursday afternoon by work in Washington and still in slick dress shoes below his shroud. He clambers up the amphitheater, over rubble above Henry’s not-quite-finished stone steps.

The show can go on.