CHAPTER XXVII

  THE LAUGH IN THE NIGHT

  Tarling gave one glance before he turned to the girl, who wasendeavouring to push past him, and catching her by the arm gentlythrust her back into the passage.

  "What is wrong? What is wrong?" she asked in a terrified whisper. "Oh,let me go to mother."

  She struggled to escape from his grip, but he held her firmly.

  "You must be brave, for your own sake--for everybody's sake," heentreated her.

  Still holding her arm, he forced her to the door of the second innerroom. His hand felt for the electric switch and found it.

  He was in what appeared to be a spare bedroom, plainly furnished, andfrom this a door led, apparently into the main building.

  "Where does that door lead?" he asked, but she did not appear to hearhim.

  "Mother, mother!" she was moaning, "what has happened to my mother?"

  "Where does that door lead?" he asked again, and for answer she slippedher trembling hand into her pocket and produced a key.

  He opened the door and found himself in a rectangular gallery overlookingthe hall.

  She slipped past him, but he caught her and pushed her back.

  "I tell you, you must be calm, Odette," he said firmly, "you must notgive way. Everything depends upon your courage. Where are the servants?"

  Then, unexpectedly, she broke away from him and raced back through thedoor into the wing they had left. He followed in swift pursuit.

  "For God's sake, Odette, don't, don't," he cried, as she flung herselfagainst the door and burst into her mother's room.

  One glance she gave, then she fell on the floor by the side of her deadmother, and flinging her arms about the form kissed the cold lips.

  Tarling pulled her gently away, and half-carried, half-supported her backto the gallery. A dishevelled man in shirt and trousers whom Tarlingthought might be the butler was hurrying along the corridor.

  "Arouse any women who are in the house," said Tarling in a low voice."Mrs. Rider has been murdered."

  "Murdered, sir!" said the startled man. "You don't mean that?"

  "Quick," said Tarling sharply, "Miss Rider has fainted again."

  They carried her into the drawing-room and laid her on the couch, andTarling did not leave her until he had seen her in the hands of two womenservants.

  He went back with the butler to the room where the body lay. He turned onall the lights and made a careful scrutiny of the room. The windowleading on to the glass-covered balcony where he had been concealed a fewhours before, was latched, locked and bolted.

  The curtains, which had been drawn, presumably by Milburgh when he camefor the wallet, were undisturbed. From the position in which the deadwoman lay and the calm on her face he thought death must have comeinstantly and unexpectedly. Probably the murderer stole behind her whilstshe was standing at the foot of the sofa which he had partly seen throughthe window. It was likely that, to beguile the time of waiting for herdaughter's return, she had taken a book from a little cabinet immediatelybehind the door, and support for this theory came in the shape of a bookwhich had evidently fallen out of her hand between the position in whichshe was found and the book-case.

  Together the two men lifted the body on to the sofa.

  "You had better go down into the town and inform the police," saidTarling. "Is there a telephone here?"

  "Yes, sir," replied the butler.

  "Good, that will save you a journey," said the detective.

  He notified the local police officials and then got on to Scotland Yardand sent a messenger to arouse Whiteside. The faint pallor of dawn was inthe sky when he looked out of the window, but the pale light merelyserved to emphasise the pitch darkness of the world.

  He examined the knife, which had the appearance of being a very ordinarybutcher's knife. There were some faint initials burnt upon the hilt, butthese had been so worn by constant handling that there was only thefaintest trace of what they had originally been. He could see an "M" andtwo other letters that looked like "C" and "A."

  "M.C.A.?"

  He puzzled his brain to interpret the initials. Presently the butler cameback.

  "The young lady is in a terrible state, sir, and I have sent for Dr.Thomas."

  Tarling nodded.

  "You have done very wisely," he said. "Poor girl, she has had a terribleshock."

  Again he went to the telephone, and this time he got into connection witha nursing home in London and arranged for an ambulance to pick up thegirl without further delay. When he had telephoned to Scotland Yard hehad asked as an after-thought that a messenger should be sent to LingChu, instructing him to come without delay. He had the greatest faithin the Chinaman, particularly in a case like this where the trail wasfresh, for Ling Chu was possessed of super-human gifts which only theblood-hound could rival.

  "Nobody must go upstairs," he instructed the butler. "When the doctor andthe coroner's officer come, they must be admitted by the principalentrance, and if I am not here, you must understand that under nocircumstances are those stairs leading to the portico to be used."

  He himself went out of the main entrance to make a tour of the grounds.He had little hope that that search would lead to anything. Clues theremight be in plenty when the daylight revealed them, but the likelihood ofthe murderer remaining in the vicinity of the scene of his crime was aremote one.

  The grounds were extensive and well-wooded. Numerous winding paths met,and forked aimlessly, radiating out from the broad gravel paths about thehouse to the high walls which encircled the little estate.

  In one corner of the grounds was a fairly large patch, innocent of bushand offering no cover at all. He made a casual survey of this, sweepinghis light across the ordered rows of growing vegetables, and was goingaway when he saw a black bulk which had the appearance, even in thedarkness, of a gardener's house. He swept this possible cover with hislamp.

  Was his imagination playing him a trick, or had he caught the briefestglimpse of a white face peering round the corner? He put on his lightagain. There was nothing visible. He walked to the building and round it.There was nobody in sight. He thought he saw a dark form under the shadowof the building moving towards the belt of pines which surrounded thehouse on the three sides. He put on his lamp again, but the light was notpowerful enough to carry the distance required, and he went forward at ajog trot in the direction he had seen the figure disappear. He reachedthe pines and went softly. Every now and again he stopped, and once hecould have sworn he heard the cracking of a twig ahead of him.

  He started off at a run in pursuit, and now there was no mistaking thefact that somebody was still in the wood. He heard the quick steps of hisquarry and then there was silence. He ran on, but must have overshot themark, for presently he heard a stealthy noise behind him. In a flash heturned back.

  "Who are you?" he said. "Stand out or I'll fire!"

  There was no answer and he waited. He heard the scraping of a bootagainst the brick-work and he knew that the intruder was climbing thewall. He turned in the direction of the sound, but again found nothing.

  Then from somewhere above him came such a trill of demoniacal laughter aschilled his blood. The top of the wall was concealed by the overhangingbranch of a tree and his light was valueless.

  "Come down," he shouted, "I've got you covered!"

  Again came that terrible laugh, half-fear, half-derision, and a voiceshrill and harsh came down to him.

  "Murderer! Murderer! You killed Thornton Lyne, damn you! I've kept thisfor you--take it!"

  Something came crashing through the trees, something small and round, asplashing drop, as of water, fell on the back of Tarling's hand and heshook it off with a cry, for it burnt like fire. He heard the mysteriousstranger drop from the coping of the wall and the sound of his swiftfeet. He stooped and picked up the article which had been thrown at him.It was a small bottle bearing a stained chemist's label and the word"Vitriol."