The Doctor was looking for Donna he was given the note by Ianto but he was given news that she wasn't in her flat. He's taking in the sites and he's bothered a few close looking red heads.

"I feel guilty." The Doctor's got a tinge of an emotional sadness in his voice and those senses kick in. He turns around to see Donna standing there and he wonders how much of her wants to see him right now.

"Been looking for you," The Doctor goes to push his feelings aside for now. "I was glad to hear Jack's friend took you in for the night." He's been worried for her, his best friend who's so full of life is just a sad, sad person right now.