"But, daddy, daddy, hold on! We'll come to you----" "It can't be done," her father interrupted crisply. "I called you to say good-by and to tell you to look after the families of the servants that are fastened up here with me." He paused a moment, and said quietly: "I'm in the library downstairs. I can hear the windows creaking. They may give way at any moment and let the horror into the house. It tried to creep in under the doorsills, but we calked them with the table linen." "Daddy!" cried Nita agonizedly. "Oh, daddy, try to fight it off just a little while! We've found a way to stop it! We can kill them all!" "I have about ten minutes more, Nita," said her father gently. "You couldn't get to me. Be a good girl, Nita----" There was a crash. "There go the windows! Good-by, Nita, good-by----" The others heard her cry out, and rushed from the music room to hear her calling, calling desperately for her father to answer her, calling into a silent phone. CHAPTER IX. Davis pounded mightily upon the great gate of the half-deserted shipyard. Behind him, Nita was sobbing in spite of her efforts to hold back her tears. Evelyn tried her best to calm Nita, but without real effect. Gerrod had shot the party out at the gate of the shipyard and darted off in the little motor car on some mysterious errand. Davis pounded again wrathfully, using a huge stone to make his blows reverberate through the yard. A workman came slowly toward them. "Hurry! Hurry!" Nita called tearfully. "Please hurry!" The workman recognized her through the palings. All of Morrison's employees knew his daughter. The workman broke into a run. The gate swung open. "Where's Mr. Keeling, the manager?" demanded Nita urgently. "We must see him at once." The workman pointed, and the three of them hurried as fast as they could walk toward the man he had indicated. "Mr. Keeling," said Nita desperately. "Father is marooned in our house up the Hudson. He may be dead by now. We've got to get to him!" "I don't know how----" began the manager helplessly. "I want a submarine siren," said Davis crisply. "One that can be tuned to different notes. Also the fastest motor boat you have. Give the necessary orders at once." "But the Silver Menace----" began the manager again. "Don't stand there talking," barked Davis in a tone that secured instant obedience. "Get the siren and the boat. And hurry! This is life and death!"