"Why can't you?"

"I—I just can't, that's all."

"But there must be a reason!"

"There is a reason."

"What?"

"Well ... to begin with ... it was never absolutely settled that I should go."

"But you told Severn to-night that you were going."

"Yes ... I thought I was going then."

"And you've changed your mind since?"

"Yes ... I suppose I have."