Jack blinks completely startled for a second. He'd been expecting a Donna Noble who didn't know him or one who hadn't met him yet. This...well this was like Christmas come early. "Donna," he said warmly, "you remember me?" The question is soft and slightly hopeful, because after everything with the Miracle and Esther Jack felt he was owed something good for a change.

And Donna Noble with her memories back is good indeed. "When did this happen?"