‘Dr Ames?’ I cried, stupefied. ‘But I thought you believed in some occult influence?’

‘You misunderstood me, Hastings. What I meant was that I believe in the terrific force of superstition. Once get it firmly established that a series of deaths are supernatural, and you might almost stab a man in broad daylight, and it would still be put down to the curse, so strongly is the instinct of the supernatural implanted in the human race. I suspected from the first that a man was taking advantage of that instinct. The idea came to him, I imagine, with the death of Sir John Willard. A fury of superstition arose at once. As far as I could see, nobody could derive any particular profit from Sir John’s death. Mr Bleibner was a different case. He was a man of great wealth. The information I received from New York contained several suggestive points. To begin with, young Bleibner was reported to have said he had a good friend in Egypt from whom he could borrow. It was tacitly understood that he meant his uncle, but it seemed to me that in that case he would have said so outright. The words suggest some boon companion of his own. Another thing, he scraped up enough money to take him to Egypt, his uncle refused outright to advance him a penny, yet he was able to pay the return passage to New York. Someone must have lent him the money.’

‘All that was very thin,’ I objected.

‘But there was more. Hastings, there occur often enough words spoken metaphorically which are taken literally. The opposite can happen too. In this case, words which were meant literally were taken metaphorically. Young Bleibner wrote plainly enough: “I am a leper”, but nobody realized that he shot himself because he believed that he contracted the dread disease of leprosy.’

‘What?’ I ejaculated.

‘It was the clever invention of a diabolical mind. Young Bleibner was suffering from some minor skin trouble; he had lived in the South Sea Islands, where the disease is common enough. Ames was a former friend of his, and a well-known medical man, he would never dream of doubting his word. When I arrived here, my suspicions were divided between Harper and Dr Ames, but I soon realized that only the doctor could have perpetrated and concealed the crimes, and I learnt from Harper that he was previously acquainted with young Bleibner. Doubtless the latter at some time or another had made a will or had insured his life in favour of the doctor. The latter saw his chance of acquiring wealth. It was easy for him to inoculate Mr Bleibner with the deadly germs. Then the nephew, overcome with despair at the dread news his friend had conveyed to him, shot himself. Mr Bleibner, whatever his intentions, had made no will. His fortune would pass to his nephew and from him to the doctor.’

‘And Mr Schneider?’

‘We cannot be sure. He knew young Bleibner too, remember, and may have suspected something, or, again, the doctor may have thought that a further death motiveless and purposeless would strengthen the coils of superstition. Furthermore, I will tell you an interesting psychological fact, Hastings. A murderer has always a strong desire to repeat his successful crime, the performance of it grows upon him. Hence my fears for young Willard. The figure of Anubis you saw tonight was Hassan dressed up by my orders. I wanted to see if I could frighten the doctor. But it would take more than the supernatural to frighten him. I could see that he was not entirely taken in by my pretences of belief in the occult. The little comedy I played for him did not deceive him. I suspected that he would endeavour to make me the next victim. Ah, but in spite of la mer maudite, the heat abominable, and the annoyances of the sand, the little grey cells still functioned!’