When you pulled us from the lake, you said the boy is important,...
Walter: When you pulled us from the lake, you said the boy is important, he must live. You weren't referring to my son, you were referring to yours.
Donald: Yes. Did he show you anything else?
Walter: Yes. And there's one thing I haven't told the others. He showed me that in order for the plan to work, I would have to sacrifice myself.