The Doctor doesn't respond for a long moment. He tosses another piece of sheet metal onto the pile and stops to take a breath and consider his options. He could stick with the lie, but he doubts he could hold onto it much longer. He's not even entirely sure what he said about the locket, much less what he said it might've done.

"I didn't know what they were going to decide," he says, finally. "I didn't want you to do something stupid and get hurt."