The news Donald Trump has caught coronavirus has thrust US politics into turmoil, raising an untold number of potential ramifications.
It is still just hours since the US president's positive result was announced, with a reassurance from the White House doctor that Trump and his wife are feeling well.
But it has already triggered a wave of speculation about what could happen to the US government, the US election, the handling of the pandemic and more.
Here, the Telegraph unpacks three potential scenarios for what could happen depending on how quickly Trump shakes off the virus.
1. Donald Trump is barely sick and returns soon
There are already two political impacts that are unavoidable however quickly the president recovers from the virus.
The first is in campaign time lost. Trump cannot visit the battleground states he needs to close the gap in or hold events with cheering supporters as he self-isolates.
The second is in a change of focus. In the coming days coronavirus will be the dominant topic in the media and polls show most Americans think he has mishandled the pandemic.
The spotlight will be shone on the many times Trump has downplayed the virus's threat and dismissed prevention measures like wearing masks. None of this is likely to help Trump's hopes of re-election. But if he has a speedy recovery, there may be political benefits.
Trump could more effectively be able to project empathy for Americans who have been impacted by the virus. His Democratic rival Joe Biden has attempted to make that a point of difference between himself and the president. Trump could declare he has beaten the virus.
The second Biden-Trump debate is scheduled for October 15, almost exactly two weeks after his positive test. Could the president return, Covid-free and triumphant?
A speedy recovery would also have implications, too, on how Trump views the virus, its risk and the way to combat it. It is possible a mild experience with the virus reinforces Trump's existing views of the pandemic, leading the president to focus even more on the need to get the economy going again.
The campaign has to this point seen both candidates try to balance two competing demands: stopping the spread of the virus and protecting businesses from the economic hit.
Could Trump push down the throttle on reopenings if his infection passes quickly? Could he become a proponent of herd immunity, the controversial strategy of allowing (to a degree) the virus to spread to build up antibodies in the public? Any such moves would fundamentally alter the coronavirus debate right before the vote.
2. Trump gets quite sick but recovers and returns
In this scenario, politically Trump could benefit from what is known as the "rally round the flag" phenomenon, in which American voters stand by the president at moments of great peril.
It is this that polling experts gave as the explanation for why Trump saw his approval rating rise to its highest point of his presidency outside the first few weeks when the outbreak first hit. The increase only lasted a few weeks.
Some voters in a nation rocked by seven million Covid-19 cases and grieving the deaths of 207,000 people from the virus could come to see Trump in a more sympathetic light.
One aspect of the policy reaction in such a scenario would be whether the illness impacted Trump's view on China and the degree of blame Beijing has for the virus's spread.
The president has already been ferociously critical of Chinese officials for not warning the world sooner, for not disclosing early enough human-to-human spread and for not letting independent US scientists in to investigate in those crucial early weeks. But, so far, all the tough talk has largely not been followed with tough action.
Would that change if Trump got pretty sick from Covid-19? Could there be sanctions, diplomatic reprimands, steps to make concrete America's disapproval? Or even tougher action?
There could also be pressure to delay the election. Trump has already floated once pushing back the November 3 date because of the pandemic. It got a quick and stern rebuke from Republican senators who would have to approve the move - Congress would need to pass a law - but Trump's illness could change things.
It is theoretically possible. The inauguration date, January 20, and not the election date is the one written in stone in the US Constitution. Why not push the election back a few weeks to make up for lost campaigning time from the illness, some Trump loyalists may ask.
However, the Democrats would also have to approve, given they hold the majority in the House of Representatives - one half of Congress - meaning bipartisan support would be needed.
3. Trump gets very sick and is yet to recover as election nears
No sitting president is known to have faced a life-threatening condition since Ronald Reagan was shot in 1981, let alone have a health crisis this close to a vote, meaning we would be in uncharted territory.
There is a tried-and-tested system in the US federal government for when presidents become incapacitated and Mike Pence, the US vice president, will be primed to step in.
Under the 25th Amendment, a medically incapacitated president can temporarily transfer power to the vice president, as George W Bush did twice during colonoscopies. Pence already runs the White House's coronavirus task force so will be fully across the fight to tackle the pandemic.
He knows the policy and the key players, plus spent four years as Indiana's governor so has experience in handling executive power. That will avoid the situation that happened in Britain when Boris Johnson was in intensive care and, critics said, there was a lack of clarity about who was in charge and how they would be kept in the loop with Covid-19 planning.
Would Pence take a different approach to the pandemic? He has certainly been less wild in his dismissals of the risk of coronavirus. Could there be other policy changes? How far would tensions with China escalate? On the political side, the impacts would be incalculable.
Already there has been loose and speculative discussion about Trump's name on the ballot and whether there could be a change. If Trump is incapacitated - or worse - as the electorate is about to make their choice for president on November 3, will there come a point when his name could be replaced?
Pence, again, would be the person almost certainly picked if that grave situation were to come about. But changing ballots would be a bureaucratic nightmare.
In many states people are already voting. In all likelihood, millions of postal ballots have already been sent out, given the increased demands for voting that way. In this scenario, again, calls for an election delay would ramp up. And they could have more merit.