Rose nodded to Donna, and skirted down a thin alleyway, relieved to see the TARDIS up ahead and practically slamming against its side. For a moment she thought they had stopped being followed; the shadows around them all seemed natural, and it was unlikely they were going to suddenly swallow them up whole, but Rose's relief was only short-term.

"Donna, hurry," she said quickly, eyes seeing the irregular pool of darkness slip towards them. She didn't want to think what would happen if they got a hold of them.