 The Doctor and Rose return to present day Earth to visit Jackie - only to find the people of Earth rejoicing as the ghosts of loved ones have arrived. The Doctor is naturally suspicious, and discovers that the nearby Torchwood Institute is responsible. But the ghosts are masking an imminent invasion from a different dimension. Which of the Doctor s oldest and greatest enemies is about to return? Which old friend is about to return when the Doctor thought he would never be seen on Earth again? And just what is the mysterious sphere in the bowels of Torchwood Tower hiding? Earth is about to become the battlefield for the most deadly war of all time...