"Behind the--oh." It hadn't occurred to her that this universe could be that different. Earth was practically the same. There wasn't a time lock? Well, there wouldn't be, would there? All that hadn't happened here. Strange that after all they'd seen, this was the part that made her head spin.
She really didn't know what sort of questions to ask. The Doctor clearly had something on his mind, working him up. She knew the time lock was a sensitive subject, and she worried asking the wrong question would get a bad reaction. She didn't want to throw him off whatever it was.