Dick gritted his teeth and swore as he circled over the site of destruction, out of which tiny figures were struggling. He heard the clang of the fire bells as the motor trucks came roaring toward the scene. Then crash! again. Five blocks northward another dense cloud of dust arose, and the new area of destruction, spreading as swiftly as ripples over a pond, joined the former one, leaving a huge, irregular open space, piled up with masonry and brick in a number of flat-topped pyramids. Into this, houses went crashing every moment, with a sound like the clatter of falling crockery, but infinitely magnified. "The devils! The swine!" shouted Dick. "And we gave Von Kettler the privileges of an ambassador!" And Fredegonde was the sister of this devil! The remembrance of that struck a cold chill to Dick's heart again. He tried to blot out her picture from his mind, but he still saw her as she had appeared that day after the air ride, flushed, smiling, radiant in her dark beauty. A murderess and a spy! He cursed her as he banked and circled back. He was helpless. He could do nothing. And all Washington would be destroyed by morning, if the supply of bombs kept up. But there was more to come. Suddenly Dick became aware that two of his flight, at widely separated distances, were going down in flames. Flaming comets, they dropped plump into the destruction below. Another caught fire and was going down. No need to question what was happening. The invisible enemy was attacking his flight and picking off his men one by one! He drove furiously toward two of his planes whose erratic movements showed that they were being attacked. As he neared them he saw one catch fire and begin its earthward swoop. Then the fuselage crackled beside him, and his instrument board dissolved into ruin. Instinctively he went round in a tight bank and loosed his machine-gun. Nothing there! Nothing at all! Yet his right wing went ragged, and his own furious blasts into the sky, their echoes drowned by the roar of his propeller, were productive of nothing. * * * * * He shot past the uninjured plane, signalling it to descend. He wasn't going to let his men ride aloft to helpless butchery. Nothing could be done until some means was discovered of counteracting the enemy's terrific advantage. He darted across the heart of the city to where another of the flight was circling, waggling his wings to indicate to it to descend. Then on to the next plane and the next, shepherding them. Thank God they understood! They were bunching toward the hangar. Yet another took fire and dropped, a burning wreck. Half his flight out of commission, and not an enemy visible!