The four-part epic first-year finale continues! Earth is under attack from an ancient species who yoked suns and spanned galaxies before we'd even evolved opposable thumbs. Cities are tumbling under their assault, people are dying in droves, and only two people in the universe can save us. But first the Doctor and Clara must save themselves! Burning with fury forged in the heart of stars, armed with technology beyond human comprehension, composed of a fleet of unstoppable warships, the Hyperions have returned at last. Welcome to the Hyperion War. Welcome to the last days of Earth!