The three larger barges were again advancing toward the Anglese coast. Without warning, without orders from Fahn, the little remnant of girls led by Azeela and Dee, darted at them. It was a movement, not foolhardy, but well and swiftly planned. The girls, holding close to the surface, got themselves between two of the barges. The Noths could not fire, for they would have struck each other. A puff of inky darkness spread over the ships, and out of it, at close range, jets of fire sprang at the Noths; then the girls came back. One of the Noth vessels was a mass of flames; the other two wavered--and began retreating. For a moment there was silence and darkness, lighted only by the moon and the flickering light from the blazing barge. The whirling blades were no longer being launched; the Anglese were again poised in the air. Fahn had ordered that the small barge be attacked when, abruptly, a low hum sounded from it. George and Loto were hovering together at the moment; the barge was some five hundred feet below them and slightly off to one side. There didn't seem to be any dogs on it; only a few men under its wire cage, and a single large piece of apparatus. The hum grew louder, more intense, as though some gigantic dynamo had been set into motion. "What's that?" George demanded. But Loto did not know. Mogruud, with the remains of his division, was in the air half a mile away. He was on the other side of the small barge; his men, moving in scattered groups, began passing over it. The hum was rising in pitch, up the scale until it became a shrill electrical scream. Mogruud's men wavered--struggled as though to avoid being pulled downward. Then Loto realized that it must be the rest of the apparatus Toroh had secured out of the past--a giant electromagnet of some unknown variety. It was pulling at every figure in the air, drawing them irresistibly toward it. Loto and George could feel the pull; invisible fingers were snatching at them. The girls near at hand were fighting against it. Mogruud was moving forward with an effort, like a swimmer struggling with the clutch of an undertow. Several of his men, closer to the barge, had been drawn to it, flattened helplessly against its wire caging. Fire was leaping through their bodies...they were electrocuted. In the cavern Fahn sat tense, impotent. He could hear, as plainly as though he were out there over the sea, the scream of that uncanny thing that was reaching out its invisible electrical fingers to gather in its victims. At his side, for the past hour, Rogers had been operating the larger mirrors, flashing into them scenes from the various towers along the coast. Now Fahn heard him give a sharp, horrified exclamation.