Giovanni began to understand, though it was the first time he had heard that the boys, like the common people, suspected Angelo Beroviero of being an alchemist.  It was clear that the boy meant the book that contained the priceless secrets for glass-making which Giovanni and his brother had so long coveted.  His interest increased.

“After all,” he said, “you saw nothing distinctly.  My father went in and shut the door, I suppose.”

“Yes,” answered the boy.  “But after a long time the door opened again.”

He stopped, resolved to be questioned, in order that his information should seem more valuable.  The instinct of small boys is often as diabolically keen as that of a grown woman.

“Go on!” said Giovanni, more and more interested.  “The door opened again, you say?  Then my father came out—­”

“No, sir.  Zorzi came out into the light that fell from the door.  The master was inside.”

“Well, what did Zorzi do?  Be quick!”

“He brought out a shovel full of earth, sir, and he carefully scattered it about over the flower-bed, and then he went back, and presently he came out with the shovel again, and more earth; and so three times.  They had buried the great book somewhere in the laboratory.”

“But the laboratory is paved,” objected Giovanni, to gain time, for he was thinking.

“There is earth under the stones, sir.  I remember seeing it last year when the masons put down several new slabs.  The great book is somewhere under the floor of the laboratory.  I must have stepped over it in feeding the fire last night, and that is why the devils that guard it inspired the porter to beat me this morning.  It was the devils that sent us to sleep, for fear that we should find it.”

“I daresay,” said Giovanni with much gravity, for he thought it better that the boy should be kept in awe of an object that possessed such immense value.  “You should be careful in future, or ill may befall you.”

“Is it true, sir, that I have told you something you wished to know?”

“I am glad to know that the great book is safe,” answered Giovanni ambiguously.

“Zorzi knows where it is,” suggested, the boy in a tone meant to convey the suspicion that Zorzi might use his knowledge.

“Yes—­yes,” repeated Giovanni thoughtfully, “and he is ill.  He ought to be brought over to the house until he is better.”

“Then the furnace could be allowed to get out, sir, could it not?”

“Yes.  The weather is growing warm, as it is.  Yes—­the furnace may be put out now.”  Giovanni hardly knew that he was speaking aloud.  “Zorzi will get well much sooner if he is in a good room in the house.  I will see to it.”

The boy stood still beside him, waiting patiently for some reward.

“Are we to come as usual to-night, sir, or will there be no fire?” he asked.

“Go and ask at the usual time.  I have not decided yet.  There—­you are a good boy.  If you hold your tongue there will be more.”