“Not impossible to those who travel through the skies and drop black stones which fly to pieces with a loud noise,” Otto calmly replied. “The beasts of the south have made alliance with Att the Terrible, and Tipi the Steadfast, and are marching with them. Good Builder! They are upon us even now. Quick, the beasts enter this very room. Come, draw, defend yourself!” Wheeling quickly, Cabot confronted Doggo standing in the doorway. Much relieved, he explained to Otto who this newcomer was; then, seizing a pad and a lead stylus of his own manufacture, he hurriedly sketched the situation to his Formian friend. In reply Doggo wrote: “At last I have magnesium ore. Some soldiers brought it in, attracted by its pretty red color. There is no time to be lost. To the laboratory. You must complete our set and summon aid from Cupia. Meanwhile I will get Jud on the air, and call him here for a conference. We have no time to wait upon him, or even Theoph, in this emergency.” Myles read the message aloud to Otto. “It is well,” the latter commented. “Now, if you will excuse me, I must be running along. My disguise as a Vairking soldier will get me safely out of your city, and I must join my father, who is planning to counter-attack, if a fit opportunity presents itself. Till we meet again.” “Till we meet again, in this life or beyond the waves,” the earth-man replied. “And may the Builder bless you for your help this day.” Then he rushed to the laboratory. Doggo was already tuning the set. “Jud is not at home,” he wrote. “Shall I waste a tube on the brickyard?” “No,” Myles signified with a shake of his head; then seizing the pad and stylus again, he wrote: “I will try and get Jud. You meanwhile attempt to extract magnesium from this piece of carnallite.” The ant-man knew exactly how to proceed. Grinding the ore, he mixed it with salt and melted the mass in an iron pot, which he connected electrically with the carbon terminal of a line of electric batteries. In the boiling pot he placed a copper plate connected with the zinc elements of his cells. By the time the earth-man returned from calling Jud on the radio, a coating of pure magnesium had begun to form on the copper anode. An hour or so later he scraped off his first yield of the precious metal, the final necessity of his projected radio set. At this stage Jud appeared. “Pardon the delay,” he started to explain. “You see, I—” But Myles cut him short with: “Never mind explanations now. It is enough that you are here. Sur has fallen. The beasts of the south and Att the Terrible are on the warpath. They seek to rob you of your Arkilu. With their aerial wagons they will drop magic rocks upon this city and destroy it. Give Doggo back his plane, and he will try to combat them.” But Jud shook his head. “You would merely escape,” he replied, “and then we would be worse off than now.” “Then you admit that you know the whereabouts of Doggo’s plane?” Myles eagerly asked.