What indeed had happened? The question took the Doctor off-guard. It shouldn't have. After all, Clara had asked him the same thing when they had been in the Cloisters. He had to think about how to answer. So many different answers he could offer. Which would be the most right for Jamie? He reached into his pocket and pulled out his Confession Dial. He presented it to Jamie for his inspection.

"I was used as a bargaining chip. Between an immortal who wanted to keep the Earth safe from the creatures I left behind and the Time Lords who wanted to extract information from me. My friend who travelled with me at the time was killed because of their game. Then the Time Lords trapped me inside of that."

He knew the next question Jamie would ask, so he started to answer before the question was asked.

"It's a Time Lord Confession Dial. It is meant to be used as a ritual act of purification. It allows a dying Time Lord to face his demons before his mind is uploaded into the Matrix. But... Not for me. For me, they found a way to turn it into a torture chamber."

He looked down and away now. He wouldn't tell Jamie everything. Not yet. It was too painful. Mixed with sending her to her death in the Library, it was too much.

"It took me over four billion years to find a way out..."

Enough of the truth to be the truth without the details that just hurt more than he could admit. Finally he looked up at Jamie again.

"I do want to help. But these days, I'd rather help without causing too many deaths."