At the mention of the farming colony, the Doctor could only give her a sort of sad but sympathetic smile and shake his head softly, as if he were trying to shake off a bad memory. He felt a shiver run through him as she took his arm, and he had to remind himself that what mattered was that Susan was here now, she was safe, it was all going to be just fine.
"OK, come on then, I'd like to see what you're driving these days anyway!" he forced a smile, trying his best to put a brave face on it for her, and it probably would have worked if it weren't for the paleness of his cheek and the memory of how he had just been behaving. How was he meant to tell her? Of course, he'd already given Romana the awful truth, but that was different. Romana had been the president for goodness sakes, this was Susan, and in his mind Susan was always going to be someone he felt the need to protect. It didn't matter how old she was now, or the amount of terrible things she had already seen both in her travels with him and in her own life... she was still his little granddaughter.