Wilfred Mott is very happy: his granddaughter, Donna, is back home, catching up with family and gossiping about her journeys, and he has just discovered a new star and had it named after him. He takes the Tenth Doctor with him to the naming ceremony. But the Doctor soon discovers something else new, and worryingly bright, in the heavens - something that is heading for Earth. It's an ancient force from the "Dark Times". And it is very, very angry. An adventure featuring the Tenth Doctor as played by David Tennant and his companion Donna.