"How can it be tried?" I asked. Instead of replying, the surgeon put a question to me, on his side.
"Do you happen to know," he said, "that this year is Leap Year?"
"Mrs. Fairbank reminded me of it yesterday," I answered. "Otherwise I might not have known it."
"Do you think Francis Raven knows that this year is Leap Year?"
(I began to see dimly what my friend was driving at.)
"It depends," I answered, "on whether he has got an English almanac. Suppose he has not got the almanac—what then?"
"In that case," pursued the surgeon, "Francis Raven is innocent of all suspicion that there is a twenty-ninth day in February this year. As a necessary consequence—what will he do? He will anticipate the appearance of the Woman with the Knife, at two in the morning of the twenty-ninth of February, instead of the first of March. Let him suffer all his superstitious terrors on the wrong day. Leave him, on the day that is really his birthday, to pass a perfectly quiet night, and to be as sound asleep as other people at two in the morning. And then, when he wakes comfortably in time for his breakfast, shame him out of his delusion by telling him the truth."
I agreed to try the experiment. Leaving the surgeon to caution Mrs. Fairbank on the subject of Leap Year, I went to the stables to see Mr. Raven.