The day in Tahrir Square began with worship. It was time when placards used for protest became prayer mats, and the faithful bowed down toward Mecca.
For nonbelievers, these early morning moments were no less profound. The square, bounded by a string of high-end hotels, the burnt-out remains of the National Democratic Party headquarters, the Egyptian Museum, and, oddly, a Kentucky Fried Chicken, felt as though it holds the embers of Egypt's future.
By nightfall, however, it was ablaze. Pro-government provocateurs on camel and horseback brandished whips as they circled the square in a surreal scene. Later, volleys of petrol bombs, bricks and tear-gas canisters flew through the air.
The showdown shattered the relative peace of the past week as both sides violently struggled to seize control of Tahrir Square, which has come to symbolize the entire country.
This was not how the day was supposed to unfold for thousands of protesters for whom this uprising has become something resembling a daily vocation.
A day after Egyptian President Hosni Mubarak vowed not to seek re-election, demonstrators felt emboldened, and ready to dig in.
An ultimate victory, signified by Mr. Mubarak stepping down, felt very much within their grasp.
Rola Zyada, a 17-year-old high school student pitched her Coleman tent on a scruffy patch of grass. Tired of commuting to "history" from her home across town, she brought two sleeping bags and a set of fresh sheets, deciding it was time to bunk in.
"I've decided to stay overnight to help my people get through this, because I think the longer we stay here and the more we are, the more it says about us," she said, squinting behind a pair of knock-off sunglasses and pursing her lips.
"The vibe is very friendly. I didn't think it would be like that, but people are helping each other out. We are cleaning, we buy food for each other, people share their tents and cover each other up," said Ms. Zyada, whose T-shirt proclaimed "Peace" and "Love" in sparkling, pastel print.
Around her, Tahrir Square was staggering to life. An old woman wrapped in a woollen shawl sold steaming cups of tea for the equivalent of 20 cents. A teenaged boy balanced a wooden basket of bread, selling for 10 cents.
Not far from Ms. Zyada's tent, a group of young men hung a red sign on theirs that read: "Freedom Motel" in both English and Arabic.
"We will be here until he leaves," one of the men said, referring to his President. "We can feel the freedom," he added, unwrapping a roll of lifesavers.
The first signs of trouble surfaced around noon when rumours started to circulate that pro-Mubarak agitators were trying to infiltrate the square to foment violence.
A column of regime supporters, hoisting handmade signs marched along the Corniche Al Nile toward Tahrir Square.
They stopped just short of an army tank manned by a handful of bored-looking soldiers, the only thing separating them from the thousands of the anti-Mubarak demonstrators inside the square who suddenly kicked into high gear.
Dozens formed a "People's Protection Force," a cordon of men who linked arms and stood shoulder to shoulder to keep the pro-regime provocateurs out.
Inside the square, new placards were painted and shuttled up to the front line: "You have sold your vote. Don't sell your country," read one, in green pain, still wet.
"Keep your loot and just leave," proclaimed another, an allusion to the widespread belief that the pro-regime supporters had been paid off -$8, according to some - to march against reform.
Meanwhile, across town, another demonstration was gathering steam. In the nouveau riche neighbourhood of Mohandessin about three kilometres away, tens of thousands of people poured onto the streets to support Mr. Mubarak and denounce his opposition, particularly the key figure of Mohamad ElBaradei.
"Coward, ElBaradei!" chanted the demonstrators, who hailed from rich and poor corners of Cairo.
Jihan Munib, psychoanalyst from Zamalek, was incensed at the protesters in Tahrir Square. "They are one million. We are eighty-six million!" she said, standing with granddaughters, aged 18 and 20.
The protests had cleaved the family. Ms. Munib's son-in-law, an ophthalmologist, was demonstrating in Tahrir Square ("I was never happy about their marriage," she confided) around which, by late afternoon, thousands of more pro-regime supporters had arrived.
As tensions rose, Egyptian security forces melted away, or stood by. For a time, it appeared the pro-Mubarak protesters would retreat. Instead, they charged the square.
The fighting lasted for hours, with pro-Mubarak demonstrators hurtling Molotov cocktails into the square and from the tops of surrounding buildings, armed with knives, sticks and swords, attempting to breach the square as their numbers swelled.
The violence came in waves, killing at least three protesters and injuring 600. The protesters inside Tahrir Square fought back with rocks and bricks pried off sidewalks.
Meanwhile, the Egyptian military surrounded the Egyptian Museum, using water cannons to stifle flames.
A chaotic, makeshift medical clinic, staffed by dozens of doctors, nursed the wounded who were treated on crude stretchers made of wood.
"We don't have enough medicine or supplies. I cannot do anything," one doctor said, searching for gauze to treat his patients' bloody head wounds.
By the end of the night, the protesters' banners were being torn up to make bandages.
- With a report from Patrick Martin in Cairo