Virgilius was fond of books, and pored over them all day long. But one afternoon, when the boys were given a holiday, he took a long walk, and found himself in a place where he had never been before. In front of him was a cave, and, as no boy ever sees a cave without entering it, he went in. The cave was so deep that it seemed to Virgilius as if it must run far into the heart of the mountain, and he thought he would like to see if it came out anywhere on the other side. For some time he walked on in pitch darkness, but he went steadily on, and by-and-by a glimmer of light shot across the floor, and he heard a voice calling, ‘Virgilius! Virgilius!’
‘Who calls?’ he asked, stopping and looking round.
‘Virgilius!’ answered the voice, ‘do you mark upon the ground where you are standing a slide or bolt?’
‘I do,’ replied Virgilius.
‘Then,’ said the voice, ‘draw back that bolt, and set me free.’
‘But who are you?’ asked Virgilius, who never did anything in a hurry.
‘I am an evil spirit,’ said the voice, ‘shut up here till Doomsday, unless a man sets me free. If you will let me out I will give you some magic books, which will make you wiser than any other man.’
Now Virgilius loved wisdom, and was tempted by these promises, but again his prudence came to his aid, and he demanded that the books should be handed over to him first, and that he should be told how to use them. The evil spirit, unable to help itself, did as Virgilius bade him, and then the bolt was drawn back. Underneath was a small hole, and out of this the evil spirit gradually wriggled himself; but it took some time, for when at last he stood upon the ground he proved to be about three times as large as Virgilius himself, and coal black besides.
‘Why, you can’t have been as big as that when you were in the hole!’ cried Virgilius.
‘But I was!’ replied the spirit.