A moment at the end of the universe...
"We should be frozen to death."
"...Martha and I perhaps. I'm not so sure about you Jack."
Their eyes meet, staring into eachothers souls. Jack feels the familiar fear at the intensity of that gaze warring with the anger inside him.
He knew. He had always known. And he had still abandoned him. Left him to work it out all alone.
They stare at eachother, each man measuring the other, noting the changes in that gaze since they last met. Jack doesn't know what kind of man he has become, let alone who the Doctor is now, but there is one thing he is sure of.
He still loves him.
That love, like Jack himself, is undying.