The reading continued, but the abbot ceased to listen. He knew the letter nearly by heart, but still he felt that there was something Marcus Apollo had been trying to say between the lines that he, Dom Paulo, had not yet managed to understand. Marcus was trying to warn him-but of what? The tone of the letter was mildly flippant, but it seemed full of ominous incongruities which might have been designed to add up to some single dark congruity, if only he could add them right. What danger could there be in letting the secular scholar study at the abbey?