The Doctor and Clara in “Mummy on the Orient Express”

I couldn't risk Gus finding out my plan and stopping me.

So you were… pretending to be heartless?

Would you like to think that about me? Would that make it easier? I didn't know if I could save her. I couldn't save Quell, I couldn't save Moorhouse. There was a good chance that she'd die too. At which point… I would have just moved on to the next… and the next, until I beat it. Sometimes the only choices you have are bad ones, but you still have to choose.