They sat on the stairs, and time went slowly by. Ione had a step to herself to begin with, but after an interval when she must have drifted into an uneasy sleep she found that there was a shoulder under her head and an arm that steadied her. It wasn’t the Professor’s arm, because the whisky seemed to be some way off… She slid back into sleep again…

It was the kind of sleep in which you keep on coming to the surface and drifting off. Whenever she did come back, the Professor seemed to be talking, the sound of his rolling r’s like the drum-beat in a dance rhythm. Presently he was saying,

“There’s that old chestnut about the mandarin in China. Ye’ll have heard it ad nauseam, but it raises a very interesting moral problem. If by pressing a button which would cause the death of this totally unknown person, ye could benefit three-quarters of the human race, would ye, or would ye not, be justified in pressing the button?”

Mr. Severn’s voice was much nearer as he said,

“How do you know that it’s going to benefit three-quarters of the human race?” The tone had a touch of boredom, a touch of amusement.

“That,” said the Professor, “ye will just have to hypothesize.”

The word rolled grandly off his tongue. Ione considered it with awe. She could not believe that it really existed, but at a more convenient time, when she was able to have recourse to a dictionary, she discovered that it did. At the moment it just floated away and became part of a general state of mind in which dream and reality kept on changing place. The floor was hard, but her ankle had stopped hurting. She heard Mr. Severn say,

“Well, three-quarters of the human race is a fairly large order, and if you get down to brass tacks, I feel pretty sure that the button-pusher is really only interested in one member of it-himself. Is he going to do himself a bit of good, or isn’t he? And if he does his button-pushing, is he going to get away with it? That’s a really very much better problem than the other, you know.”