It had been thought the Xeelee had forgotten us. They had not forgotten.
We called the Xeelee’s vengeance the Scourge. It was a simple strategy: the stars that warmed human worlds were cloaked in an impenetrable shell of the Xeelee’s fabled ‘construction material’. It was even economical, for these cloaks were built out of the energy of the stars themselves. It was a technology that had actually been stumbled on long before by human migrants of the Second Expansion, then rediscovered by the Coalition’s Missionaries – discovered, even colonised, but never understood.
One by one, the worlds of man fell dark. Cruellest of all, when humanity had been driven out, the Xeelee unveiled the cleansed stars.
People had forgotten how to fight. They fled to the home Galaxy, and then fell back further to the spiral arms. But even there the scattered stars faded one by one.
It took the Xeelee three hundred thousand years, but at last, a million years after the first starships, the streams of refugees became visible in the skies of Earth.
-Resplendent, "Between Worlds"