A great entity, spanning across a thousand timelines, and mentioned in the cultures of a thousand worlds, had its attention focused on the Earth. However, it was different from many of the other aliens that had set their attentions on that particular planet, for it was neither interested in the planet itself, nor the humans that inhabited it. It was after only one thing, the one reason why humans had survived so long, the one being that had saved the Earth, and indeed the universe, time and time again.

It was after a Time Lord, and no power in the whole of creation was going to stop it.

Jack roused himself when he noticed that he was beginning to doze off. "Damned Cardiff," he muttered, irritated by the lack of sleep and the lack of leads on his current project. He pulled at the leather band around his wrist to ease an itch, but paused and looked down when the itch grew into a tingle, and then to a burn. He shook his head. Either his eyes were playing tricks on him, or the leather wristband was glowing a faint yellow-orange colour.

When Ianto walked ten seconds later, Jack had disappeared.

Sandra spotted the three figures almost too late, and slammed on the brakes, her car fishtailing wildly on the wet surface of the road.

"Jack!" the Doctor shouted desperately, before the darkness took him, and he collapsed and tumbled the rest of the way down the stairs.

"I've seen this before," Jack muttered. "Come on! We've got to get back to the Doctor!"

"What is it?" Green asked, still sitting next to the Doctor.

"Outside," murmured Brittany. "There is something outside."

The creature reared up, eyes glowing red in the gloom. With a low roar, it smashes through the window to the bedroom, and locked its gaze onto the Doctor. Then it attacked.

The Doctor, Brittany and Captain Jack Harkness will return in Forest of Shadows.