At nine o'clock that night the last visit was to be paid the prisoners. At nine o'clock Maraglia, the Castellan, came, attended by the guard, which waited outside. The Castellan was in a state of nervous excitement. As he entered Tristan's cell he looked about, as if he dreaded a listener, then he approached his prisoner and whispered something into his ear. For a moment Tristan knew not what has happening to him. Was he alone with a mad man and was Maraglia too possessed?-- The Castellan, to prove his assertion that he was a bat, began forthwith to squeak, and waved his arms, as if they were wings. Curious stories were told about Maraglia. No one knew, why he had retained his post so long amidst ever recurring changes, and it was whispered that he was subject to strange possessions of the mind. He faced his prisoner nervously, fingering a poniard in his belt. Tristan watched his every gesture. A little foam came out of the corners of Maraglia's lips. He wrung his hands and his voice rose into a sort of shriek. He jerked his head half round towards the men-at arms outside in the gallery. The screams of Hormazd continued. "It is the Ape of Antichrist," he whispered to Tristan. "I have a mind to try conclusions with him. Close the door." Tristan's wits, preternaturally sharpened in his predicament put words in his mouth which he seemed unable to account for. He had heard rumors of the Castellan. Perchance he might turn his madness to account. "I can tell you much," he said. "But not here! But one thing I perceive. You are approaching one of your bad spells." Maraglia shrank back against the door. His face was pale as death. "Then you know?" he squeaked. Tristan nodded. The torch which the Castellan had placed in an iron holder that projected from the wall, was burning low and the resinous fumes filled the cell. "Something I know--but not all! Yet, I believe I can cure you--" "I am about to turn into a bat! And when I go abroad I scream like a bat--in a thin, high pitched tone. And I flap my arms--and fly away--thus--" Tristan nodded wisely. "I know the symptoms--they are of Satan. Nevertheless, I can cure you." "Without conference with the evil powers?" Tristan pondered. "You shall not imperil your soul! But--take heed! It is well that you have spoken to me of these matters. For, from feeling that you are a bat, a bat you will become." Maraglia was pale as a ghost. "Then I was just in the nick of time?" "You are already half immersed," Tristan replied in a deep and menacing tone. "Take heed lest you be utterly drowned." The Castellan shivered as one in an ague. "Every Friday at midnight the Black Mass is said by one Bessarion, that is of unthinkable age--a hideous wizard and High Priest of Satan. It is he who has cast the spell over me."