The runaway bride sets out to find her Time Lord.

Donna Noble is determined to find the Doctor again – even if it means braving the villainous Miss Foster and her hordes of sinister Adipose, as Russell T Davies's Bafta Award-winning time-travelling drama returns for a fourth series. But when the alien threat escalates out of control, can Donna find her Time Lord before the march of the Adipose begins?

There was another squealing sound from high above. Donna wondered what it was. The Doctor already seemed to know, and dragged her protesting over the sodden ground and towards the truck. 'Take cover!' he yelled. 'The bombardment has started!' 'Incoming!’ bellowed Harrison from the middle distance. A dull crump sounded from beyond the truck, and a fountain of black earth spurted up into the air and scattered over them. There was a fizzing sound of energy. The remaining soldiers leapt out of the transport vehicle, fresh weapons in their hands. Harrison had appeared by Donna's side. He was looking to her for orders, she realised. She wasn't in uniform, she wasn't able to command him, and all because of a simple misunderstanding. Harrison's eyes glazed over. He toppled face forward and sprawled in the mud. Only then did Donna know what the fizzing sound was. Weapons were firing. Harrison had been shot dead in front of her. The dun-coloured shapes of more soldiers scurried past, taking positions. It took Donna a moment to work out what they were doing: they were aiming their rifles upward. She followed the direction of their weapons. She stared in disbelief. Donna could make out thin legs on fat, swollen bodies dropping from the invisible sky. The air was alive with gunfire as the creatures fell through the fog and clattered to the ground. 'Oh my God,' she breathed. 'Doctor, they're dropping ponies on us!' Not exactly,' he said, pulling her behind the truck. Donna slithered in the mud, and landed on her bum. She could feel the water soak right through. The Doctor was still talking: 'Look again. Horses don't have parachutes.'