“The problem presents features of interest,” said he. “I may even say exceptional features of interest. I have already looked into the matter, and have come, as I think, within sight of my solution. If you could accompany me in that last step you might be of considerable service to me.”

“I should be delighted.”

“Could you go as far as Aldershot tomorrow?”

“I have no doubt Jackson would take my practice.”

“Very good. I want to start by the 11:10 from Waterloo.”

“That would give me time.”

“Then, if you are not too sleepy, I will give you a sketch of what has happened, and of what remains to be done.”

“I was sleepy before you came. I am quite wakeful now.”