"A business conference."
"A business conference of which your secretary knew nothing?"
"Certainly. A very confidential conference."
"Did anyone besides yourself know that you were going to Oxford?"
"Both my partners."
"What proof can you give me that you actually were in Oxford last night?"
"What the devil has my visit to Oxford got to do with Fletcher's murder?" North demanded. "Of course I can bring proof! I dined at my college, if you must know, and spent the evening with my old tutor."
"When did you leave your tutor?"
"Just before midnight. Anything else you'd like to know?"
"Nothing else, thank you. I shall ask you presently to give me the name and address of your tutor, so that I can just check up on your story."