The stone is as harsh and unremitting as the hot sun.
The story is as obdurate and hard as Pennsylvania granite.
Looking down on the emerging foundations at the archaeological excavation of the President's House, you can see a drama that - as the site reveals - was well-developed at the birth of the nation and continues to this day.
It is the drama of slavery present at the heart of liberty, and, ultimately, the drama of race in America.
The drama is evoked by the symbolic potency of the findings unearthed at Sixth and Market Streets, site of the house where slave-holding George Washington and antislavery John Adams conducted their presidencies in the 1790s.
And now visitors and officials alike are raising the question: How long should this drama run?
"The truth is finally there to see," one black woman said as she gazed out thoughtfully over the welter of stone foundations. Here is where the first presidential family and its chattel slaves once lived in what can now be seen as walled-off but close parallel worlds.
"They should leave this," she murmured, almost to herself.
As thousands of visitors swarm across the platform erected in Independence National Historical Park to facilitate viewing of the dig, comments about race and power, black and white, slavery and freedom, history and identity are everywhere in the air.
(When the site - previously viewable only on weekdays - was opened last weekend, more than 1,000 people visited, stunning Park Service officials, who have opened it again this weekend from 9 a.m. to 5 p.m.)
Because of this intensifying interest, city and Park Service officials are seriously reconsidering how to proceed with the site.
Should they stick with the goal of completing the dig this month and refilling the hole in time for July Fourth celebrations? Or should they devise some alternative that keeps the site open?
And what should be done about the ultimate plan to build a memorial to the house and its occupants, including Washington's nine slaves, over the filled-in excavation? Designers headed by Kelly/Maiello Architects & Planners are already well into the planning process. Should they change course?
These issues are being revisited, city officials said last week. And Karen Warrington, a member of an advisory committee overseeing site plans, said "there is a need for further discussions."
What has evoked this response to the two-month-old dig?
Toward the end of April, about 10 feet below street level, archaeologists uncovered the foundation for the back wall of the main house, which was demolished in 1832 and replaced by three commercial buildings fronting Market Street.
That was good news, but not much of a surprise.
What really energized archaeologists and the public was the discovery a few days later of the foundation and basement of the house's kitchen building, about 20 feet south of the main house. There had been no documentary evidence that the kitchen even had a basement, archaeologists said.
During Washington's presidency, his enslaved African chef, Hercules, well-known for his culinary artistry, presided over that kitchen, which other slaves and indentured servants staffed.
A day or two after that find, another stone foundation was discovered - remnants of an underground passageway from the kitchen basement to the main house's basement. The passage allowed slaves and servants to move back and forth unseen.
The passageway had also been unknown.
A few days later, archaeologists uncovered the foundation for a large bow window that Washington had installed at the rear of the house. During his presidency, according to historians, Washington would stand at this window and greet dignitaries and the public.
The excavation now starkly shows the world of Washington and his grand window and, six feet away, the world of Hercules and the other slaves.
"Here," said one man on the platform, pointing to the window, "the powerful."
Sweeping his finger over to point at the kitchen, "Here, the powerless."
African Americans visiting the site often are deeply affected.
George Peebles of Philadelphia was almost speechless as he looked over the maze of walls the other day.
"Wow," he said, shaking his head. "Wow. They buried the ugliness of slavery, and it's just being uncovered centuries later.
"It shows how our history as Africans was covered up. For sure. Literally buried. Now it's a historical thing. But back then, just the ugliness of it - that's what gets me."
It is, he said, "the real deal."
Warrington, who is African American and a member of the project's committee of historians, officials and community members, said the site made it possible to talk about identity in a personal way.
"So many of us grew up without a clue of who we were," she said. "It's not even something you can explain."
Looking at the site, she said, evoked "those people reaching up out of the soil, telling their story. It's a monument of what happened."
Cheryl Janifer LaRoche, a historical archaeologist, has spent many hours on the platform explaining to visitors what they are looking at.
"I love this view without the walls because it strips away a lot," she said the other day, surrounded by people on the platform. "I think about walls a lot. This walling away is so symbolic for this site. Now you see this small space between here [at the bow window] and there [at the kitchen] is the space between the great statesman working out his understandings of democracy and the people that he enslaved."
"Yes," said a woman, "and the people who were slaves were not too far away. But they had to come up to serve him."
People, black and white, craned their necks to get a better look.
LaRoche said discussions of race between blacks and whites were often impeded by a "guilt component" in whites and a "shame component" in blacks. But the viewing platform at the President's House has provided a way around such emotional blockage.
This dig "is creating a space - I don't want to say of comfort, that's not the right word - it's creating a space of possibility for discussion," LaRoche said. "It's an opportunity to touch a chord in the past, and it's an opportunity to touch a past that's been so maligned and hidden, buried and walled away. . . .
"What I am seeing is so vast, and the possibility of what I am seeing is so profound, I'm having trouble, in my mere mortal self, talking about it."
To view a video of the excavation
at the President's House and read more about the dig, go to http://go.philly.com/presidentshouseEndText