the great magician zog never slept. he was always watchful and alert. some strange power warned him that his prisoners were about to escape.

scarcely had the four left the castle by the broken window when the monster stepped from a doorway below and saw them. instantly he blew upon a golden whistle, and at the summons a band of wolf-fish appeared and dashed after the prisoners. these creatures swam so swiftly that soon they were between the fugitives and the dome, and then they turned and with wicked eyes and sharp fangs began a fierce attack upon the mermaids and the earth dwellers.

trot was a little frightened at the evil looks of the sea wolves, whose heads were enormous, and whose jaws contained rows of curved and pointed teeth. but aquareine advanced upon them with her golden sword, and every touch of the charmed weapon instantly killed an enemy, so that one by one the wolf-fish rolled over upon their backs and sank helplessly downward through the water, leaving the prisoners free to continue their way toward the opening in the dome.

zog witnessed the destruction of his wolves and uttered a loud laugh that was terrible to hear. then the dread monster determined to arrest the fugitives himself, and in order to do this he was forced to discover himself in all the horror of his awful form, a form he was so ashamed of and loathed so greatly that he always strove to keep it concealed, even from his own view. but it was important that his prisoners should not escape. hastily casting off the folds of the robe that enveloped him, zog allowed his body to uncoil and shoot upward through the water in swift pursuit of his victims. his cloven hoofs, upon which he usually walked, being now useless, were drawn up under him, while coil after coil of his eel-like body wriggled away like a serpent. at his shoulders two broad, feathery wings expanded, and these enabled the monster to cleave his way through the water with terrific force.

zog was part man, part beast, part fish, part fowl, and part reptile. his undulating body was broad and thin and like the body of an eel. it was as repulsive as one could well imagine, and no wonder zog hated it and kept it covered with his robe. now, with his horned head and its glowing eyes thrust forward, wings flapping from his shoulders and his eely body—ending in a fish's tail—wriggling far behind him, this strange and evil creature was a thing of terror even to the sea dwellers, who were accustomed to remarkable sights.

the mermaids, the sailor and the child, one after another looking back as they swam toward liberty and safety, saw the monster coming and shuddered with uncontrollable fear. they were drawing nearer to the dome by this time, yet it was still some distance away. the four redoubled their speed, darting through the water with the swiftness of skyrockets. but fast as they swam, zog swam faster, and the good queen's heart began to throb as she realized she would be forced to fight her loathesome foe.

presently zog's long body was circling around them like a whirlwind, lashing the water into foam and gradually drawing nearer and nearer to his victims. his eyes were no longer glowing coals, they were balls of flame, and as he circled around them, he laughed aloud that horrible laugh which was far more terrifying than any cry of rage could be. the queen struck out with her golden sword, but zog wrapped a coil of his thin body around it and, wrestling it from her hand, crushed the weapon into a shapeless mass. then aquareine waved her fairy wand, but in a flash the monster sent it flying away through the water.

cap'n bill now decided that they were lost. he drew trot closer to his side and placed one arm around her. "i can't save you, dear little mate," he said sadly, "but we've lived a long time together, an' now we'll die together. i knew, trot, when first we sawr them mermaids, as we'd—we'd—"

"never live to tell the tale," said the child. "but never mind, cap'n bill, we've done the best we could, and we've had a fine time."

"forgive me! oh, forgive me!" cried aquareine despairingly. "i tried to save you, my poor friends, but—"

"what's that?" exclaimed the princess, pointing upward. they all looked past zog's whirling body, which was slowly enveloping them in its folds, toward the round opening in the dome. a dark object had appeared there, sliding downward like a huge rope and descending toward them with lightning rapidly. they gave a great gasp as they recognized the countenance of king anko, the sea serpent, its gray hair and whiskers bristling like those of an angry cat, and the usually mild blue eyes glowing with a ferocity even more terrifying than the orbs of zog.

the magician gave a shrill scream at sight of his dreaded enemy, and abandoning his intended victims, zog made a quick dash to escape. but nothing in the sea could equal the strength and quickness of king anko when he was roused. in a flash the sea serpent had caught zog fast in his coils, and his mighty body swept round the monster and imprisoned him tightly. the four, so suddenly rescued, swam away to a safer distance from the struggle, and then they turned to watch the encounter between the two great opposing powers of the ocean's depths. yet there was no desperate fight to observe, for the combatants were unequal. the end came before they were aware of it. zog had been taken by surprise, and his great fear of anko destroyed all of his magic power. when the sea serpent slowly released those awful coils, a mass of jelly-like pulp floated downward through the water with no remnant of life remaining in it, no form to show it had once been zog, the magician.

then anko shook his body that the water might cleanse it, and advanced his head toward the group of four whom he had so opportunely rescued. "it is all over, friends," said he in his gentle tones, while a mild expression once more reigned on his comical features. "you may go home at any time you please, for the way through the dome will be open as soon as i get my own body through it."

indeed, so amazing was the length of the great sea serpent that only a part of him had descended through the hole into the dome. without waiting for the thanks of those he had rescued, he swiftly retreated to the ocean above, and with grateful hearts they followed him, glad to leave the cavern where they had endured so much anxiety and danger.