His breath is knocked out of him by the blast, and with it goes the last of his strength. He'd not been expecting Voldemort, nor the Dementors which follow in his wake.

That was stupid of him. Now as he slumps to the ground, unable to move, he realizes it could also be fatal. The Dementors aren't allowed to linger as they herd Voldemort's prisoner on - into Hogwarts, into my school, no, no - but they take the hopes of everyone still living in this part of the tunnel.

I've failed, I've lost, I've let them all down, oh, please no

But even in the thrall of the Dementors, he is still Albus Dumbledore. He reaches for the cartouche round his neck.