“Of course,” he answered, whereon Higgs broke in: 

“There, that will do; you don’t want us both to kiss the Book, do you?  Who sold you that ring, and where have you been for the last dozen years, and whence do you come now?”

“I have been a prisoner of the Khalifa’s among other things.  I had five years of that entertainment of which my back would give some evidence if I were to strip.  I think I am about the only man who never embraced Islam whom they allowed to live, and that was because I am a doctor, and, therefore, a useful person.  The rest of the time I have spent wandering about the North African deserts looking for my son, Roderick.  You remember the boy, or should, for you are his godfather, and I used to send you photographs of him as a little chap.”

“Of course, of course,” said the Professor in a new tone; “I came across a Christmas letter from him the other day.  But, my dear Adams, what happened?  I never heard.”

“He went up the river to shoot crocodiles against my orders, when he was about twelve years old—­not very long after his mother’s death, and some wandering Mahdi tribesmen kidnapped him and sold him as a slave.  I have been looking for him ever since, for the poor boy was passed on from tribe to tribe, among which his skill as a musician enabled me to follow him.  The Arabs call him the Singer of Egypt, because of his wonderful voice, and it seems that he has learned to play upon their native instruments.”

“And now where is he?” asked Higgs, as one who feared the answer.

“He is, or was, a favourite slave among a barbarous, half-negroid people called the Fung, who dwell in the far interior of North Central Africa.  After the fall of the Khalifa I followed him there; it took me several years.  Some Bedouin were making an expedition to trade with these Fung, and I disguised myself as one of them.

“On a certain night we camped at the foot of a valley outside a great wall which encloses the holy place where their idol is.  I rode up to this wall and, through the open gateway, heard some one with a beautiful tenor voice singing in English.  What he sang was a hymn that I had taught my son.  It begins: 

‘Abide with me, fast falls the eventide.’

“I knew the voice again.  I dismounted and slipped through the gateway, and presently came to an open space, where a young man sat singing upon a sort of raised bench with lamps on either side of him, and a large audience in front.  I saw his face and, notwithstanding the turban which he wore and his Eastern robe—­yes, and the passage of all those years—­I knew it for that of my son.  Some spirit of madness entered into me, and I called aloud, ‘Roderick, Roderick!’ and he started up, staring about him wildly.  The audience started up also, and one of them caught sight of me lurking in the shadow.