London was once again a city of migrants yesterday. For the second time in two weeks, the capital's streets were filled not with the usual cars and buses but thick, snaking columns of people on the move.These refugees from the city did not march with wagons piled high or bundles on their back, but with suitcases on wheels and mobile phones in their hands - just as they had a fortnight ago. Told that the London Underground had been closed, they were setting off on the long march back home."Oh no, not again," was the first thought to pass through Isabelle Hans's mind. A charity worker, she found herself barred from her office just around the corner from Warren Street tube, the building hidden behind the blue and white plastic ribbons of a police cordon - just as it had been on July 7.Initial word suggested a macabre rerun of that fateful day: four explosions, three trains and a bus, one blast for each point of the compass around the centre of London.The pattern looked identical, so Londoners repeated their own behaviour, as if weary veterans of this new form of urban warfare.They texted their friends and family; they picked up snippets of news from portable radios or the internet; they cut short their working day and left offices in mid-afternoon for a journey on foot which they knew could take several hours.Even if the ritual was a repeat, the mood seemed different. Much was made of the stoicism of Londoners on July 7, an unruffled calm exhibited even by those who narrowly escaped the attacks. Yesterday, by all accounts, was not like that.Witnesses at the Oval station and elsewhere said that once they heard the sound of an explosion, or breathed in the acrid smell of smoke, passengers fell rapidly into a collective panic.There were reports of desperate stampedes as people rushed to get off trains and out of stations.One man at Warren Street station showed the television cameras a pile of sandals and flip-flops he had collected - abandoned by their owners as they "ran for their lives".Caitlin Jackson, 22, was at Leicester Square station as it was being evacuated."I never saw people move as fast as that in my life. Everybody was quiet, it was all silent. But they had that panicked look on their faces."Perhaps on July 7 the sheer surprise of the attacks numbed Londoners' reactions. The memory of July 7, the fear that they were about to experience an equally lethal rerun, seems to have had the opposite effect yesterday.The atmosphere lifted a bit once word spread that there were no fatalities. There was little of that July 7 tremble in the voice yesterday."It's more fascination than panic," said David Sanderson, a business analyst at the Abbey bank, who had headed out in the lunch hour only to be shut out of his place of work. He joined the crowd behind police lines at Warren Street, waiting and watching.He was on the normally thronging thoroughfare of Tottenham Court Road, now quiet, filled with pedestrians and the occasional fire engine or police car. In common with several roads in the capital, what is usually a traffic-filled artery had become little more than a wide pedestrian path.But once the panic subsided, it was not the stubborn resilience of London cliche that was revealed. Instead there was frustration, irritation and a glimpse of the one thing terrorists crave most: fear and a glum recognition that maybe life cannot go on as normal.Dean Seddon, 23, had made the salesman's journey to London from St Helens - against his wife's wishes. "She was going mad with me for coming," he said. At Charing Cross station he had been faced with a "wave of people, saying 'Run! Run!'" And now he thought his wife was right. Pulling his trolley-suitcase, hoping he could somehow get back to Merseyside, he had resolved not to come back to the capital "for a while" at least.Heidi Ashton, 20, had her three-year-old son asleep in a pushchair and had made up her mind too. No more buses or tubes for her, and certainly not for her child. Ms Jackson had just got off the phone after speaking to her parents, back in her native Canada. They had told her that enough was enough; it was time to come home."Personally, I'm feeling a lot of anxiety; I'm pissed off," said Martina Leeven, 35, an officer with the Changing Faces charity. That morning, she had asked herself whether it was really safe to travel on the Underground. She had decided not. Pointing at her orange trainers, she told how she had, for the first time, done the hour's walk from Bethnal Green instead. "I'm wondering, is this my life now?"She felt angry, not so much at the politicians or even the terrorists, but at "the state of the world".Her colleague, Michelle Bativala, agreed. The revelation that one of the July 7 bombers had been a primary school teacher had shaken her badly. "Before you were looking for someone fanatical," she said. "Now it could be anyone."Ms Leeven said she had not seen anyone rushed or panicked, but rather "walking around with a question mark on their faces." It seemed to describe London itself: not quaking - yet - nor deluged with fresh grief. But etched with a giant question mark, wondering what tomorrow might bring.