'Open Sesame' which will lead you to the place where the treasure is--greater treasure than was in the cave of the forty thieves. These performances which you will have gone through will have unlocked, unbolted and unbarred. All that remains is that you slide that whole side of the mantelpiece to the left. You'll have no difficulty. Behind you'll discover a cupboard, deep though narrow, going far back into the wall, with shelves laden with treasures. On those shelves is the quarter of a million of money--I daresay more--which once was Cuthbert Grahame's, waiting for some one to carry it away! Here are the two drawings which are the key to the riddle. I present them to you freely. They were made specially for you. Although the broker's man is in for rent, and the bill of sale men clamour at the door, and you are penniless, and ruin stares you in the face--ruin utter and complete--though your need of it's so great, you'll not get that money which is hidden in the mantelpiece--you'll not dare! you'll not dare! Because the bed still stands in the room--you can see it now!--the bed on which you murdered Cuthbert Grahame; and Cuthbert Grahame still lies on it--you can see him too!--waiting and watching for you to return to where you threw the pillows on the floor--waiting and watching for you. You'll not dare go back into that room again, because in it the dead hand is waiting to grip you by the throat. And after to-morrow it will be too late--Cuthbert Grahame's money will be there no longer. Here are the drawings. I will leave them with you, as I said. You will be able to study them at your leisure, conscious of who is looking over your shoulder." Margaret laid the drawings on the coverlet. With her portfolio again beneath her arm she quitted the room, as noiselessly as she had entered. All the time Mrs. Gregory Lamb had not moved or spoken a word. CHAPTER XXX MRS. LAMB IN SEARCH OF ADVICE On the evening of that same day, at the door of Mr. Isaac Luker's little house in that _cul-de-sac_ near Stamford Street, some one knocked, in a rather unusual manner, as if after a prescribed fashion, then whistled half-a-dozen sharp, shrill notes up the scale. This performance was repeated thrice before anything happened to show that it had attracted attention within. Then a window was opened above; the solicitor's head came out. "Who's there?" A feminine voice replied-- "It's me--Isabel. I want to speak to you. Don't keep me waiting out here. Come down! let me in at once." There was a brief pause before the answer came, as if the man of law was endeavouring to see as much of his visitor as he could. "Not much--I won't have you in this house; don't you think it; I'm not a fool. If you won't go without a fuss I'll soon get those who'll shift you." "You are a fool. I don't want money from you, or anything of that kind. I want to tell you something--that's all."