The Doctor had been just about to call for Donna again when he felt the sudden need to side step a bit to avoid the girl that was running full speed towards him. Dressed something like a savage. And with a little robotic dog rolling after her. Honestly, it took him a second to realize exactly who it was bolting into his TARDIS and shouting for his attention. After all, it had been so very long since he'd seen her. Hundreds of years and all that.
But when it sank in he was momentarily distracted from his need to shout after Donna some more. She was a big girl, she could take care of herself. Most of the time, at least. And besides, he'd get back to calling after her in no time.
Smiling, he followed Leela into the TARDIS, shoving his hands into his pockets as he walked. "I'm over here, actually," he started simply, leaning on the railing for a moment as he took in the sight of one of his companions long past. "Hello, Leela. It's been a while. Oh, I've got a new face, by the way. But all in all it's still me."
Not one to allow himself to go silent for long, or to even stop to let people take in the information they've been given before continuing, the Doctor went on, his mind moving to brand new questions as he started walking towards her again. "What are you doing here? You stayed behind on--" That was a statement he didn't want to finish, one that led to even more problems. Ones that wiped the smile right off his face. "You shouldn't be here." Really, she shouldn't actually exist any more.