They were once close allies, two Brexit conservatives with an important role in government, who led Great Britain in the difficult situation of the pandemic.
They then became mortal enemies when the student stabbed the teacher in the back and began a fruitless campaign to suppress his work.
Now the poisonous rivalry between Boris Johnson and Rishi Sunak has reached a dramatic third act, an extraordinary struggle to regain control of the Conservative Party after the disaster of Liz Truss's brief tenure.
"Rishi is the acceptable face of the Tories," said a party insider who knows both men well, "whereas Boris has a monstrous appetite and a huge ego - he wouldn't have got where he is without him." , he continued.
For Sunak, victory would mark an improbable comeback, just six weeks after he was completely beaten in the last race of the leadership.
For Johnson, however, a comeback would be even more unlikely. No ousted prime minister has returned to number 10 in almost 40 years, since Labour's Harold Wilson in 1974. No one since Bonnar's Law in the 1920s has led the Conservative Party twice.
The leadership race has been shortened to last just a single week this time, and nominees must secure the support of at least 100 Tory MPs by Monday afternoon to go ahead to a final vote by the party's grassroots.
MPs are beginning to declare their allegiance already, with Sunak currently in the lead and Johnson in second place. For both men, it's all to play for until Monday at 2 p.m.