Scene fourteenth exhibits Carlos in a remote monastery with a Prior, with whom he awaits the arrival of the Marquis of Posa. The Prior retires, and the prince relates to his friend the ill success of his petition, and his further alienation from the king. He tells him also of the mysterious summons, and his interview with the lady of Eboli; shows the king's love-letter to her, and exulting, asserts that such a document is sufficient to free the queen from her matrimonial obligations. Posa warns him against the arts of the princess, and unfolds her character; reasons against the blind passion which still rages in the bosom of the prince, arouses his sense of shame, rebukes him for his madness, and overwhelms him with the consciousness of guilt. He obtains possession of the letter, and having listened to the expressions of remorse and warm trust in him, which fall from the lips of his repentant friend, rewards him by permitting him to seek an audience with Elizabeth. The zealous politician perceives that the only way to lead the prince to the fulfilment of his far-reaching designs, is to take advantage of the queen's influence over him. The third act opens in the king's sleeping chamber. Philip is alone; a table, with a burning lamp, is near him, on which he leans in deep thought, gazing upon a letter and a medallion lying before him. These have been taken recently from a casket belonging to the queen, and sent as proof of her guilt to the jealous sovereign, whose first words show that the poison is working. He calls Count Lerma from the adjoining chamber, and addresses him; but the unsuspicious old man cannot comprehend the mysterious hints of the agitated monarch. _Count Lerma_. My greatest—my best king—— _Philip_. King—only king! And ever king! No better answer this Than the dull solemn cavern's empty echo! Upon this rock I strike, and will have water— Water, to quench my burning fever's thirst— He gives me glowing gold! Lerma is dismissed and Duke Alba summoned; the letter is shown to him, and he says he recognizes the prince's hand writing; encouraged to speak freely, he mentions the fact of the presence of Carlos with the queen in the garden at Aranjuez. After this information the king suddenly changes his manner; haughtily dismisses the duke, and calls his confessor. Domingo's evidence is in substance the same with that of his fellow conspirator, but his doubts are more cautiously and artfully expressed. Having heard him through, Philip recalls Alba, and charges both with a plot for the destruction of his son: alluding to Alba's hostility, he remarks— How gladly would the innocent man now arm His petty spite with my wrath's giant arm! I am the bow, ye think in your wild fancies, That may be bent for service at your will! Yet have I mine own pleasure, &c.