Savioli – who had a hand in the matter. Wassertrum is one of those men with eyes that can see through walls, but he still cannot conceive that there are minds which are capable of working out how to insert long, invisible, poison-tipped needles through such walls, between the masonry, past gold and precious stones, to pierce the hidden vital artery.”

Charousek slapped his hand against his forehead and gave a wild laugh. “Aaron Wassertrum will soon find out! On the day he thinks he has Savioli at his mercy! On that very day! That’s another chess game I’ve worked out, right down to the last move. This time it’ll be the king’s bishop’s gambit. There’s no move I can’t counter with a crushing reply, right to the bitter end. Anyone who accepts my king’s bishop’s gambit will end up dangling in the air, I tell you, helpless as a puppet on a string, and I’ll be pulling the strings, do you hear, I’ll be pulling them and then it’ll be goodbye to free will for him!”

Charousek was talking feverishly. I looked at him in horror. “What have old Wassertrum and his son done to you to fill you so full of hate?”

Charousek waved my question away. “Forget that! Ask instead what it was that broke Dr. Wassory’s neck. Or would you like to discuss it another time? The rain’s stopping, perhaps you want to get home?” He had lowered his voice, like someone who has suddenly come to his senses. I shook my head.

“Have you heard how they cure glaucoma nowadays? No? I’ll have to explain it to you if you’re to understand everything, Herr Pernath. Glaucoma is a malignant disease of the eyeball that leads to blindness and there is only one means of stopping its progress, an operation called an iridectomy in which a wedge-shaped sliver of the iris is snipped out. There is an unavoidable side-effect: the patient suffers from glare for the rest of his life. Usually, however, he is saved from total blindness.

But there is one odd fact about the diagnosis of glaucoma: there are times, especially in the initial stages of the disease, when the symptoms, although they have previously been most clearly evident, seem to disappear completely. In such cases it is impossible for a doctor, even though he cannot detect the slightest trace of the disease, to say for certain that his colleague who examined the patient and diagnosed glaucoma must have been wrong.

But once the iridectomy, which can, of course, be carried out on a healthy eye as well as on a diseased one, has been performed, it is impossible to determine whether glaucoma had been present or not.

It was on this and other factors that Dr. Wassory based his fiendish plan. Time after time he diagnosed glaucoma – especially in women – when the patient was suffering from some relatively harmless complaint, just so that he could perform an operation which was simple for him, but which brought in a lot of money.

You see, Herr Pernath, the people he had in his power were completely defenceless; fleecing them demanded no courage at all. The degenerate predator had found a territory where it could devour its prey without needing strength or claws. Without taking any chances! Do you understand?! Without risking anything!

By getting a large number of spurious articles published in the scientific journals Wassory had acquired the reputation of an outstanding specialist; he had even managed to pull the wool over the eyes of his colleagues, who were far too decent and naive to see through him. The logical result was a stream of patients looking for help. Whenever someone went to him with a minor impairment of their vision, he immediately set about his devilish plan. First of all, he questioned the patient in the usual manner, but to cover himself for all eventualities he was careful only to note down those answers which were compatible with glaucoma. He also carried out a thorough check as to whether the patient had already been examined by another doctor. In the course of his conversation with the patient, he would casually let drop that he had been urgently called abroad on professional business and would have to leave the following day.

His next step was to examine the patient, and when, in the course of this, he shone the light into the patient’s eyes, he deliberately caused as much pain as possible. All part of his plan! All part of his plan!

When the examination was over and the patient had asked the natural question, ‘Was there anything to fear’, Wassory played the opening move of his gambit. He would sit down facing his patient, wait for a good minute and then pronounce, in measured, sonorous tones, “Blindness in both eyes is inevitable in the near future.”

Not surprisingly, the scene that followed was harrowing. Often the people would faint, cry or scream and throw themselves to the ground in desperation.

To lose one’s sight is to lose everything.

Then, when the moment came, as it invariably did, when the poor victim was clasping Wassory’s knees and begging him for the love of God to help them, the fiend made his second move and transformed himself into a god in the patient’s eyes by offering him a chance of saving his sight.

Everything in the world is like a game of chess, Pernath, everything.

“If we operated immediately”, Wassory would muse, almost as if he were debating with himself, “there might just be a chance; anyway, it’s the only hope.” Then his vanity would take over and he would launch into a bombastic tirade consisting of long-winded descriptions of various cases, all of which were supposed to bear an uncommon similarity to the present one, and a list of the countless patients whom he had saved from blindness. He basked in the feeling that he was some kind of higher being, charged with the welfare of his fellow-men.

All the while his hapless victim, the cold sweat of terror on his – or, more often, her – forehead, would sit there, not daring to interrupt the torrent of words for fear of angering the one person that could help him.

Unfortunately – thus Wassory would conclude his harangue – he would not be able to perform the operation until after he had returned from his journey abroad, in a few months time. It was to be hoped – hope sprang eternal – that it would not be too late by then.

Naturally the patients would leap up in horror, insisting that they were under no circumstances prepared to wait one day longer, and plead with him to advise them as to which of the other eye-specialists in the city he might recommend to carry out the operation.