"Perhaps I had better go," Mark said. "Come with me, Miss Sartoris. Let us leave together. It will be better for you that way." "No," Mary said gently. "I am greatly obliged to you, but I shall stay." "Both stay, please," Field said in a gentler tone. "Mr. Ventmore, let me make you the most handsome apology in my power. I am afraid that this thing has got a little on my nerves. You see, this is a great case, a far greater case than anybody is aware of. I only stumbled on the real truth of it more or less by accident to-day. And if there is anything like a struggle, your help may be of value." Mark let the matter pass. He could quite understand Field's feeling. Another quarter of an hour slipped away; the road was now quite deserted, so that the wheels of a coming cab could be heard a long way off. There was a little discussion between the cabman and his fare, followed by the banging of a door, and the heavy footsteps came staggering up the street and a big man passed before the gate of No. 100, Audley Place. With a sign, Field motioned his companion to steal behind the bushes. "One of our birds, unless I am greatly mistaken," he said. "Yes, he is coming this way." Mary held her breath now, for she did not fail to recognise the newcomer. She could see from a casual glance that it was Bentwood. He came with a lurch and a stagger which proved his condition. He seemed a little suspicious at first, but the silence of the house, the steady gleam of the light over the fanlight, seemed to dispel any suspicions. Then he advanced more boldly to the door. As he stood on the bottom step, Field emerged from his hiding-place. "Doctor Bentwood," he said, "I fancy I am not mistaken. You will oblige me by taking your hand off the bell. Nobody will answer your ring." Taken aback for a moment, Bentwood stepped off the path. He bent and gripped Field by the throat. "You little beast!" he hissed. "I'll kill you. If you only knew who you are talking to!" But Field was made of whipcord and steel. He slipped away from the other's grip and planted two or three body blows that caused Bentwood to groan aloud. Mark stepped out at once, but there was no need of his services. Field was all over his man by this time. As he clenched and drove his left home, Bentwood came heavily to the ground. Before he could stagger to his feet again, Field had the handcuffs on him. "It's an outrage," Bentwood blustered, though his face was white now and his big red cheeks shook like a jelly. "What does it all mean?" "Case of Sir Charles Darryll," Field panted. "We know all about that. We shall have your friend Sartoris, in a minute, to say nothing of Reggie and Cora. If you tell us everything and make a clean breast of your part of it----" "Shan't," Bentwood said sullenly. "You can find out that for yourself." Field pursed his lips in a soft whistle. The two shadows by the gate came up.