"I go on, then, to the day before your brother's death," continued Pratt. "Namely, a certain Friday. Now, if you please, I'll invite you to listen carefully to certain facts--which are indisputable, which I can prove, easily. On that Friday, the day before your brother's death, Mrs. Mallathorpe was in the shrubbery at Normandale Grange which is near the north end of the old foot-bridge. She was approached by Hoskins, an old woodman, who has been on the estate a great many years--you know him well enough. Hoskins told Mrs. Mallathorpe that the foot-bridge between the north and south shrubberies, spanning the cut which was made there a long time since so that a nearer road could be made to the stables, was in an extremely dangerous condition--so dangerous, in fact, that in his opinion, it would collapse under even a moderate weight. I impress this fact upon you strongly." "Well?" said Nesta. "Hoskins," Pratt went on, "urged upon Mrs. Mallathorpe the necessity of having the bridge closed at once, or barricaded. He pointed out to her from where they stood certain places in the bridge, and in the railing on one side of it, which already sagged in such a fashion, that he, as a man of experience, knew that planks and railings were literally rotten with damp. Now what did Mrs. Mallathorpe do? She said nothing to Hoskins, except that she'd have the thing seen to. But she immediately went to the estate carpenter's shop, and there she procured two short lengths of chain, and two padlocks, and she herself went back to the foot-bridge and secured its wicket gates at both ends. I beg you will bear that in mind, too, Miss Mallathorpe." "I am bearing everything in mind," said Nesta resolutely. "Don't be afraid that I shall forget one word that you say." "I hear that sneer in your voice," answered Pratt, as he turned, unlocked a drawer, and drew out some papers. "But I think you will soon learn that the sneer at what I'm telling you is foolish. Mrs. Mallathorpe had a set purpose in locking up those gates--as you will see presently. You will see it from what I am now going to tell you. Oblige me, if you please, by looking at that letter. Do you recognize your mother's handwriting?" "Yes!" admitted Nesta, with a sudden feeling of apprehension. "That is her writing." "Very good," said Pratt. "Then before I read it to you, I'll just tell you what this letter is. It formed, when it was written, an invitation from Mrs. Mallathorpe to me--an invitation to walk, innocently, into what she knew--knew, mind you!--to be a death-trap! She meant _me_ to fall through the bridge!" CHAPTER XV PRATT OFFERS A HAND