The chanting never stops. Nor does the flailing with chains. And the emotional intensity just keeps rising for Iraqi Shiite Muslims on their first free pilgrimage in a generation. They pound their chests so hard in unison that the ground the seems to shake beneath them.
Columns of humanity - hundreds of thousands of pilgrims, on foot and some limping after days on sticky hot roads - are pouring into Iraq's holy city of Karbala, to mark one of the most sacred events in the Shiite calendar - and the end of Saddam Hussein's ruthlessly secular regime.
But just as Iraq's long-repressed Shiite majority enjoy a religious reawakening, the scale of the event is a show of strength for Shiite clergy who are moving quickly to fill the vacuum left by Mr. Hussein before American forces do.
"These public demonstrations are ... to express Shiite power to the Americans," says Sheikh Abdul Mahdi al-Karbalai, the top Shiite cleric in Karbala.
"If America really likes Iraq, it should leave Iraqis to our fate," he says. "If it is a real liberator, it shouldn't force a government on us."
As up to a million pilgrims converge on Karbala this week, passing through the gilt-domed shrines of Abbas and Hussein, the topic of conversation is when American troops will leave Iraq - and what kind of government they will leave behind.
Politics and religion never mixed in Saddam Hussein's Iraq, where clerics kept a low profile, rarely wearing their robes in public, and the faithful were regularly accused of dissent and tortured by security services.
While gratitude toward America runs deep for toppling Hussein, Iraqi Shiites say they expect the US to honor promises of democracy, and to go home soon.
American forces are camped on the outskirts of Karbala, and the conventional wisdom Tuesday was that they would not risk a provocation on crowded streets by entering the city.
But midmorning, even as pockets in the crowd chanted anti-American and anti-Israeli slogans, two US Humvees drove through the masses to the edge of the Abbas Mosque, with soldiers in sunglasses waving self-consciously like beauty queens on parade.
"We don't want the Americans driving here - we want them to go," says Haidar Ghazi, a religious student with a close-cropped beard. "It does not feel like democracy. When I see those two vehicles, I think it is the same as Saddam Hussein."
One Muslim said the US soldiers had been "stupid" to conduct such a brazen act as driving through the crowd, but he then pointed to surging crowds on their way to the sacred sites, to explain a broader issue. "Look at this," the man said. "Do you really want democracy here?"
That is what Iraqis say they want, adding almost uniformly that they want it with little American influence. While Shiite clerics in poor neighborhoods of Baghdad have been talking tough about creating an Islamic state - one in which women would be forced to cover their hair, and games and dancing would be outlawed - those from southern Iraq sounded a more pluralistic note Tuesday.
"We want all people to have their human rights. Sunni and Shiia are like brothers," says Sheikh Faisal al-Assadi, a gray-bearded senior theologian at the authoritative Hawza seminary in Najah, when asked about desires for an Islamic state. "Christians and Jews, we defend them like ourselves. That is true Islam."
Mr. Assadi says those who suffered under the regime of Hussein - the cleric describes his torture in the 1980s in detail, and shows his left hand, which was broken and is still swollen - should be the ones who have the right to rule now.
"I want a government for Iraqis, run by the men with broken hands," he says.
That somber note was in keeping with events in Karbala this week, which marked the 40th day of mourning today after the day that Hussein, grandson of the Muslim prophet Mohammed, died here.
One blood-spattered child was carried aloft holding a sword, while adults slapped their bloodied heads with bloodied hands to show the depth of their mourning.
Such public scenes have been unheard of for more than 25 years; the new freedom brought other scenes and horrific stories.
Street hawkers sold five different CD-ROMs for less than $1 each that were billed as scenes of government torture of dissidents. One CD was labeled "The Tyrant."
Accused of being too religious and a threat to the regime, Assadi says he was sentenced to death in 1980, and endured three years of torture before being released in 1991 as part of a Gulf War amnesty. He parts the crowd and pulls back his brown and blue clerical robes to show how his arms were tied behind his back.
He was hung from the ceiling with 25 pounds of weight strapped to his feet. He also says he saw the fate of another sheikh who refused to confess to a political crime: First his jailers applied a hot clothes iron to his skin, then attached electrodes to his body. Later they brought in, stripped, and raped his wife, and then his daughters.
"I saw it with my own eyes," the bespectacled cleric says. He also saw the destination of the other sheikh's family, when he still refused to confess. The sheikh's baby was tortured and killed.
Such harsh experience makes Assadi, and many other Iraqis, suspicious of any exile as a new ruler.
"We don't want a minister or a president who came from another country," he says. "We lived here, and we suffered from the government, and risked our lives here, and along comes the USA with its army and says it wants democracy. We want America to stick to its promise."
Some Iraqis are not convinced. Singling out Ahmed Chalabi, an Iraqi in exile for 45 years, favored by the Pentagon to rule Iraq, Karbala's leading cleric says that continued US support for Mr. Chalabi is causing resentment. Iran's Islamic government is not a model for Iraq, says Sheikh Karbalai, because unlike Iranians, Iraqis are a religious and ethnic mix.
"The people of Iraq are very well educated, can lead themselves, and have patience of thousands of years," says Abdulrassoul Ali, a cleric from Karbala, at the ornate blue-tiled entrance of the Abbas Mosque.
"The Americans will not stay - they don't want to," Mr. Ali says. "They have finished their job, and should go home."