Looking nervous but entirely determined, the prime minister's message this morning won't surprise anyone who knows her well: she will fight the challenge to her leadership with everything she has.
But all the doubts, all the anxieties, all the unhappiness about the prime minister's leadership that have crystallised around the conundrum of Brexit have finally come to a head.
Her party - not the opposition, not Parliament - deciding that her time may be up.
But the prime minister who promised she would be strong and stable is instead at the top of a party that looks weak and chaotic at a vital time.
She's in this position, her critics say, because of the choices and missteps she has made.
But her supporters would say it was because for some people in the Tory party who have had years of fury about Europe, nothing would ever have been good enough.
One of her cabinet colleagues is predicting a "long day" but a "solid win".
Let's see. Digital protestations this morning from her colleagues online that they will back her don't necessarily translate into a win in a secret ballot.
And if the prime minister wins, purgatory for a year, for those who are bitterly angry about her plans for Brexit. Their criticisms can't translate into anything more than shouts of protest.
Purgatory for her too, carrying on with a Brexit compromise that right now she just can't yet pass.