The stars had joined them. And now they should separate them forever.
Contrary to popular belief, there are lives that intersect, but their stars. When your stars are intertwined with others, form constellations. The simpler the more complex. But the universe knew the star as the Doctor and Rose Tyler were made to one day be joined.
They had a unique beauty together. If supplementing and forming the largest and most complex constellation of all. It was great, magical, beautiful and amazing. Surely one of the most wonderful works of the universe.
Over the universe would have an hour to play its part to separate them.
They say that the human tragedies comovem nations, in that case, their separation had repaired the veil of parallel worlds, but had made the universe cry.
And the universe cried again when he burned a star just to say goodbye. And he sang, sang the most beautiful song I knew. For nothing in the story could sadder than that separation. Only if they would see only one more time. The last time she would see him with that look. The last time she would see him as the man she had fallen in love.
The last time she'd see him, actually.
And it was all the fault of the stars that had joined them.