I saw by this time that I need not hesitate further to tell the doctor the truth. I disliked the task, but I saw it would not be safe to leave him any longer in ignorance of his condition. There as no telling what other preposterous tales he might invent. So I said to him gently:
“Doctor, your last remark makes it easier for me to tell you that the first words you said to me on this vessel showed me that you were not right. I kept it from our new friends here, and I thought I had better tell you how you are, so you can be a little cautious. You talk all right on most subjects, but you will do well to avoid the moon as a topic of conversation. If the others ask any more questions about the moon, you can just let me answer them.”
I said all this seriously enough, but the doctor laughed boisterously as he answered:
“Well, if this isn’t a joke. You think I am crazy, and I know you are crazy, and I can prove it. I will just ask you one question, which please answer truthfully. Don’t you remember Mona?”
“Oh, there is Mona again! Don’t you see that only proves your own madness? No, I don’t remember Mona, and you don’t either.”
“I must say,” returned the doctor, “I never expected to see you get over your infatuation so quickly.”
“What direction did my infatuation, as you call it, take?”
“Marriage, I should say.”
“Now you interest me,” I returned, “and you must tell me more. Is this Mona of yours the sole resident of the moon, of whom you spoke to Thorwald?”
“Certainly she is, but you surely must be out of your head to call her my Mona—I want no stronger proof.”