There was the whiff of panic hanging over it all.
The prime minister's team had invited me in for a last-minute interview with Boris Johnson.
Five o'clock Tuesday evening, in his Commons office.
The mementoes of a political career are scattered around: an Olympic flag, a mocked-up plastic bus stop - with his name written on it as the destination.
A framed newspaper front page marking a moment of victory.
But was this the moment that marked his defeat?
The prime minister had decided he had to confront the awkward truth that the people who speak on his behalf hadn't been telling the truth, for days on end.
As I left, one of his most loyal ministers was heading the other way up the stairwell.
Others from "team Boris" - those who originally championed him as a prospective Conservative leader - were summoned too.
Already it was obvious he was in peril. And then, for him, it got a whole lot worse.
His health secretary, Sajid Javid walked. Walking matters, but words matter too.
"The British people rightly expect integrity from their government," he said.
Yes, you heard that right. A man who sat around the cabinet table this morning, serving at the highest level in government, had concluded what the government's critics have been saying for months: it, and its leader, don't have integrity.
The now former chancellor, Rishi Sunak, went further: the public expects the government to conduct itself "properly, competently and seriously".
The man who sat alongside the prime minister this morning saying the government is none of those things.
He also, incidentally, said he had concluded he couldn't share a platform with Mr Johnson this time next week to set out a joint economic strategy to address the cost of living crunch.
There was a huge policy disagreement there too, on the most important issue for millions and millions of people right now.
Suddenly, what we were witnessing was the potential collapse of the government.
But hold on.
As I type these words at just after half-past seven, we haven't had a cabinet resignation for about an hour-and-a-half.
Plenty of cabinet ministers have made it known they are staying.
And Boris Johnson is not - until we hear otherwise - someone expected to go easily.
Things remain, to put it gently, fluid.
The only question that matters tonight is, will Boris Johnson survive? The simple truth is we don't know.
And here's another thing. Neither does he. He's no longer in control of events, or in control of his government. He has never faced a more perilous day in office.