"You're a fool, you're a fool!" he stormed, "you don't know what's coming to you. You don't know." "Perhaps I do," she said. "Perhaps I can guess. But whatever is coming to me, as you put it, I prefer that to marrying you." He started back as though she had struck him across the face, and he turned livid. "You won't say that when----" He checked himself and without another word left the room, and she heard his heavy feet blundering down the stairs. And then she met him again. It was two nights after. She met him in a horrible dream. She dreamt he was flying after her, that they were both birds, she a pigeon and he a hawk; and as she made her last desperate struggle to escape, she heard his hateful voice in her ear: "Maisie, Maisie, it is your last chance, your last chance!" She had gone to bed at ten o'clock that night, and it seemed that she had hardly fallen asleep before the vision came. She struggled to sit up in bed, she tried to speak, but a big hand was over her mouth. Then it was true, it was no dream. He was in the room, his hand upon her mouth, his voice in her ear. The room was in darkness. There was no sound save the sound of his heavy breathing and his voice. "They'll be up here in five minutes," he whispered. "I can save you from hell! I can save you, Maisie! Will you have me?" She summoned all the strength at her command to shake her head. "Then keep quiet!" There was a note of savagery in his voice which made her turn sick. For a second she filled her lungs to scream, but at that instant a mass of cotton-wool was thrust over her face, and she began to breathe in a sickly sweet vapour. Somebody else was in the room now. They were holding her feet. The voice in her ear said: "Breathe. Take a deep breath!" She sobbed and writhed in an agony of mind, but all the time she was breathing, she was drawing into her lungs the chloroform with which the wool was saturated. At two o'clock in the morning a uniformed constable, patrolling his beat, saw an ambulance drawn up outside a house in Doughty Street. He crossed the road to make inquiries. "A case of scarlet fever," said the driver. "You don't say," said the sympathetic constable. The door opened and two men walked out, carrying a figure in a blanket. The policeman stood by and saw the "patient" laid upon a stretcher and the back of the ambulance closed. Then he continued his walk to the corner of the street, where he found, huddled up in a doorway, the unconscious figure of a Scotland Yard detective, whose observation had been interrupted by a well-directed blow from a life preserver. CHAPTER XV THE COMMISSIONER HAS A THEORY "To all stations. Stop Ambulance Motor No. LKO 9943. Arrest and detain driver and any person found therein. Warn all garages and report.--COMMISSIONER." This order flashed from station to station throughout the night, and before the dawn, nine thousand policemen were on the look-out for the motor ambulance.