Things have changed in just a few days in ways that would normally take years to evolve.
Whitehall had been monitoring and fearing the arrival of the coronavirus on these shores for many weeks.
But when Boris Johnson told us not so long ago that we would face a significant challenge from coronavirus, who could have imagined how the mounting cases of the disease in the UK would touch nearly every aspect of our lives?
Now, after a frenetic few days in Westminster, the government machine is working at breakneck speed to manage the health service, and drastically improve its capacity; it has made a huge decision to close schools that will affect millions of families' daily lives and the education of a generation of children; it has provided what could be a temporary bridge, or evolve into a permanent bailout of huge chunks of the economy; negotiated new arrangements, or is in the middle of doing so with the insurance industry, the supermarkets, the travel and aviation industries, and tonight the Treasury is frantically trying to design a new method of providing welfare to those who need it and financial support to businesses struggling to keep afloat and keep paying wages.
And that really may only be the start.
The idea of a protracted policy process of vague green papers, setting out policy, then white papers, setting out drafts of new laws, then Parliament chewing over legislation for months seems like something from another world now.
The government is not, as things stand, about to shift to a much more draconian approach that other countries have pursued.
It is ministers' hope to manage the situation in the expectation that it may be around for many many months.
And despite the prime minister's attempt to offer a more hopeful promise to the country that we could "turn the tide" in 12 weeks, it's not the expectation in Downing Street that this threat will soon disappear.
He talked hopefully about the possibility of a significant increase in testing, and the possibility of science moving fast enough to find solutions.
But making the virus manageable for now, and the future, is the goal, to give the health service time to adapt to confront it, rather than any expectation of making the coronavirus quickly disappear altogether.
There is the prospect too of a short, sharp shock to the economy but the real possibility of a prolonged and very real recession.
Inside government the evidence is already there of people losing their jobs. This is an economic fight perhaps as much as a medical one, with resilience and moral actors too.
Remember for the vast majority of people who contract the virus it is a mild illness. But it is dangerous for vulnerable groups, and its wider impact on our way of life is already profound.
The government's mantra has been to hope for the best, but prepare for the worst. But no-one can know yet what that might really be.