In his turn, Adam entertains Raphael with a description of his amazement when he awoke on a flowery hillside, to see the sky, the woods, and the streams; his gradual acquaintance with his own person and powers, the naming of the animals, and his awe when the divine master led him into Paradise and warned him not to touch the central tree. After describing his loneliness on discovering that all living creatures went about in pairs, Adam adds that, after he had complained to the Creator, a deep sleep fell upon him, during which a rib was removed from his side from which to fashion Eve. Joined by the Creator himself to this "bone of his bone and flesh of his flesh," Adam declares since then they have enjoyed nuptial bliss, and artlessly inquires whether angels marry and are given in marriage too. Whereupon Raphael rejoins that in heaven love so refines the thoughts and enlarges the heart that none save spiritual communion is necessary to secure perfect bliss. Then, seeing the sun about to set, the angel takes leave of Adam and wends his way back to heaven, while the father of mankind rejoins his waiting wife. Book IX. The poet warns us there will be no more question of talk between man and angels, as his song must now change to a tragic note, because vile distrust has entered Paradise. Then he describes how Satan, driven away from Eden by Gabriel, circles around the earth seven days and nights without rest, and at the end of that time re-enters Paradise, by means of an underground river and in the guise of a mist. Then, perched as a bird upon the tree of knowledge of good and evil, Satan decides to approach our first parents in the guise of a loathsome serpent and seek his revenge, although fully aware the consequences will recoil upon himself. Next, finding a serpent asleep, Satan enters it, and meanders along the paths of Paradise, hoping to find Adam and Eve apart, for he deems it will be easier to work his ends on one at a time.