Morning breaks in London with a strange, exhilarating silence: Gone is the constant low hum of two dozen jetliners overhead, the scores of vapour trails etched in the sky.
Gone, too, are couriers, tourists, fresh fruit. The silent city sounds and feels like a village, bathed in sunlight and frozen in stillness. The air tastes sweet, and the sky is perfectly clear and crystalline for the first time in a decade.
You realize, as never before, that you live on an island.
The cloud of ash emanating from an Icelandic volcano has shut down every major airport in Western Europe for the past five days, including the major hubs that link Asia, Africa and North America to one another. The shutdown will continue deep into Monday at the very least, British officials announced last night, and it will take another week after flights resume to get everyone back home.
The timing of this uncontrollable act of geology could not have been worse: it occurs at the end of a two-week Easter school holiday during which a large part of the population of Britain, and several other countries, takes advantage of no-frills airfares to go overseas. Hundreds of thousands of people are stranded abroad - and tens of thousands of foreigners are stranded here and in the other major cities of Europe.
This morning, schools will reopen to half-full classrooms, businesses will scramble to cover for missing executives, and embassy officials will work overtime to try to bail out stranded vacationers.
This is a continent utterly devoid of air traffic and air-related commerce for the first time since the days after Sept. 11, 2001, and for a much longer duration - a place that feels cut off from the world, and in many concrete ways is.
Air shipments of fresh fruit and exotic vegetables from the Mediterranean, flowers from North Africa, grain from Asia and transplant organs from across Europe have been suspended for five days, leading to shortages and some reports of panic buying.
Several schools and universities, including faculties at Cambridge University, have suspended exams due to take place this week because not enough students are likely to return.
It is a mood that older people remember from the transatlantic isolation of the Second World War. As if in homage, British politicians have begun to adopt the language, and some of the tactics, of wartime. Cabinet ministers emerged from an emergency meeting at 10 Downing Street yesterday to declare that they will deploy Royal Navy and commercial vessels to get 200,000 stranded Britons back from the Continent and the shores of the Mediterranean.
"We plan to mobilize whatever logistical capability we can to get them back home," business secretary Peter Mandelson, who is Prime Minister Gordon Brown's most senior minister, announced.
One London newspaper, the Independent, declares it "Mandelson's Dunkirk" on today's front page.
Forms of transportation that had been neglected have leapt back into the mainstream. Ferries across the English Channel are booked to capacity, with no chance of getting a seat on the channel-tunnel Eurostar train.
And the cruise ship, formerly a vessel of slow-paced leisure, has suddenly become a the fastest possible transatlantic option for many business people desperate to get back.
"We have a lot of Canadian executives calling to ask about emergency bookings on the Queen Mary II, because they know it might be the fastest way back under these conditions," said Stuart MacDonald, head of the Canadian cruise-booking site Tripharbor.
That ship, with 2,620 passengers, sails from England on Thursday, and is 10 per cent overbooked; Cunard, its owner, is now charging a non-refundable $500 just to get onto the waiting list. Some travel experts say its six-day passage may beat the first flights available to stranded passengers.
More desperate than those well-off business people, though, are those on the cheapest holidays: Those who booked family breaks on EasyJet or Ryanair for a few hundred pounds, on working-class incomes, and now find themselves forced to find full-price, non-package family hotel rooms in an expensive holiday-resort city for what could be weeks.
There is another group of even more desperate people: Families who had been en route from the Indian subcontinent and East Asia to North America on Thursday and found themselves stranded in European airports. For the past five days, scores of these families have been living, feeding and entertaining themselves. Without visas for European countries, they can't step out of the airport.
The Canadians stuck in Europe - there appear to be several thousand, though embassies say they have been too busy helping people with visa and travel emergencies to keep count - are mostly facing far less urgent emergencies.
"It was meant to be a very short visit to celebrate my aunt's birthday, but it's turned into two weeks of my vacation time, and it might be a lot more," said Victor Apps, a Toronto accountant who has found himself staying on relatives' couches in London.
Mr. Apps was supposed to run in the Boston Marathon Monday, and had spent the winter raising pledges for the race. He is scrambling to find another marathon, and is one of innumerable Canadians searching for flights later this week.
But, like many of those stranded in Britain this weekend, he marvelled at the clear skies and silence. "If I'm going to be stranded somewhere, this is a pretty nice way to do it."