I nodded.  He changed the theme.

‘This that you’re engaged upon,—­is it a projectile or a weapon?’

’If you are a member of the next government you will possibly know; if you aren’t you possibly won’t.’

‘I suppose you have to keep this sort of thing secret?’

’I do.  It seems that matters of much less moment you wish to keep secret.’

’You mean that business of last night?  If a trifle of that sort gets into the papers, or gets talked about,—­which is the same thing!—­you have no notion how we are pestered.  It becomes an almost unbearable nuisance.  Jones the Unknown can commit murder with less inconvenience to himself than Jones the Notorious can have his pocket picked,—­there is not so much exaggeration in that as there sounds.—­Good-bye,—­thanks for your promise.’  I had given him no promise, but that was by the way.  He turned as to go,—­then stopped.  ’There’s another thing,—­I believe you’re a specialist on questions of ancient superstitions and extinct religions.’

‘I am interested in such subjects, but I am not a specialist.’

’Can you tell me what were the exact tenets of the worshippers of Isis?’

’Neither I nor any man,—­with scientific certainty.  As you know, she had a brother; the cult of Osiris and Isis was one and the same.  What, precisely, were its dogmas, or its practices, or anything about it, none, now, can tell.  The Papyri, hieroglyphics, and so on, which remain are very far from being exhaustive, and our knowledge of those which do remain, is still less so.’

’I suppose that the marvels which are told of it are purely legendary?’

‘To what marvels do you particularly refer?’

‘Weren’t supernatural powers attributed to the priests of Isis?’

’Broadly speaking, at that time, supernatural powers were attributed to all the priests of all the creeds.’

‘I see.’  Presently he continued.  ’I presume that her cult is long since extinct,—­that none of the worshippers of Isis exist to-day.’

I hesitated,—­I was wondering why he had hit on such a subject; if he really had a reason, or if he was merely asking questions as a cover for something else,—­you see, I knew my Paul.

‘That is not so sure.’

He looked at me with that passionless, yet searching glance of his.

’You think that she still is worshipped?

’I think it possible, even probable, that, here and there, in Africa—­Africa is a large order!—­homage is paid to Isis, quite in the good old way.’

‘Do you know that as a fact?’

’Excuse me, but do you know it as a fact?—­Are you aware that you are treating me as if I was on the witness stand?—­Have you any special purpose in making these inquiries?’

He smiled.

’In a kind of a way I have.  I have recently come across rather a curious story; I am trying to get to the bottom of it.’