Ending
It is Dumbledore's words which began Voldemort's demise and they are his that end it.
"It contains a force that is at once more wonderful and more terrible than death, than human intelligence, than the forces of nature.
It is also perhaps the most mysterious of the many subjects for study that reside there. It is the power held within that room that you posse in such quantities and which Voldemort has not at all. It was your heart that saved you."
I know now it was also love.
The End.