“And now,” he said, taking Kafka’s hand, “I would advise you to rest as long as you can.  I suppose that it must have been a fatiguing trip for you, though I myself am as fresh as a May morning.  There is nothing wrong with you, but you are tired.  Repose, my dear boy, repose, and plenty of it.  That infernal Sicilian doctor!  I shall never forgive him for bleeding you as he did.  There is nothing so weakening.  Good-bye—­I shall hardly see you again to-day, I fancy.”

“I cannot tell,” answered the young man absently.  “But let me thank you,” he added, with a sudden consciousness of obligation, “for your pleasant company, and for making me go with you.  I daresay it has done me good, though I feel unaccountably tired—­I feel almost old.”

His tired eyes and haggard face showed that this at least was no illusion.  The fancied journey had added ten years to his age in thirty days, and those who knew him best would have found it hard to recognise the brilliantly vital personality of Israel Kafka in the pale and exhausted youth who painfully climbed the stairs with unsteady steps, panting for breath and clutching at the hand-rail for support.

“He will not die this time,” remarked Keyork Arabian to himself, as he sent the carriage away and began to walk towards his own home.  “Not this time.  But it was a sharp strain, and it would not be safe to try it again.”

He thrust his gloved hands into the pockets of his fur coat, so that the stick he held stood upright against his shoulder in a rather military fashion.  The fur cap sat a little to one side on his strange head, his eyes twinkled, his long white beard waved in the cold wind, and his whole appearance was that of a jaunty gnome-king, well satisfied with the inspection of his treasure chamber.

And he had cause for satisfaction, as he knew well enough when he thought of the decided progress made in the great experiment.  The cost at which that progress had been obtained was nothing.  Had Israel Kafka perished altogether under the treatment he had received, Keyork Arabian would have bestowed no more attention upon the catastrophe than would have been barely necessary in order to conceal it and to protect himself and Unorna from the consequences of the crime.  In the duel with death, the life of one man was of small consequence, and Keyork would have sacrificed thousands to his purposes with equal indifference to their intrinsic value and with a proportionately greater interest in the result to be attained.  There was a terrible logic in his mental process.  Life was a treasure literally inestimable in value.  Death was the destroyer of this treasure, devised by the Supreme Power as a sure means of limiting man’s activity and intelligence.  To conquer Death on his own ground was to win the great victory over that Power, and to drive back to an indefinite distance the boundaries of human supremacy.