thinking he fumbled for the hole and slipped in the key. To his surprise it turned under his involuntary pressure, and the door swung open noiselessly. Again the constable scratched his head. Things--so he assured himself--were becoming mysterious, and he scented an adventure. It was strange that this key should open the door. "Unless this is his home, and he's running away for some devilment. Maybe the lady isn't his sister; perhaps his wife or his sweetheart. Augh! But she'd not let him go at this hour. Catch her."
However he might argue, it was foolish to stand before an open door without doing something. The inspector would be round soon, and might--probably would--demand an explanation. Now that he had got this far, Mulligan naturally decided to see the adventure through. As yet he had no suspicion that anything was wrong, though he certainly thought the whole affair mysterious. Walking into the dark hall, at the end of which, by the light of his lantern, he saw the glimmer of a marble staircase, he called gently up into the blackness. "Is there any one there?" demanded Mulligan. "If so, come down, for I'm in want of an explanation."
He paused and listened. There came no reply. The dense silence held the house. Not even a clock ticked. Mulligan suppressed his breath and listened with all his ears. No sound filled them save the drumming of his heart. Again he ran into the garden and again assured himself that the light was burning overhead. He began to conclude that the position called for the intervention of the law. Assuming an official air, he tramped up the stairs, flashing the light right and left as he ascended. He did not know the position of the room, save that it was in the front of the house. But thus indicated, he thought there would be little difficulty in finding it and solving the mystery.
From the glimpses he caught, the house appeared to be richly furnished. He saw pictures, velvet curtains, marble statues, and all the paraphernalia of a wealthy man's mansion. The stairs were draped with scarlet hangings, contrasting vividly with the whiteness of the polished marble. On the landing, curtains of the same flamboyant hue were parted before another dark hall. Mulligan crossed this, for he saw--or thought he saw--a thread of light beneath a door. The hall was of marble and filled with tropical plants. A glass roof overhead revealed the starry night and the grotesque forms of the plants. The flooring was of mosaic, and here and there stood velvet-cushioned chairs, deep and restful. Evidently the house was owned by rich and artistic people. And the fitful gleams from his lantern exaggerated the wealth and splendour around.
In spite of the noise made by his boots--which were anything but light--no one appeared to demand the reason of his intrusion. He began to feel an eerie feeling creeping over him. This silent, lordly house, the darkness, the stillness, the loneliness: it was all calculated to appeal strongly--as it did--to the Celtic imagination of the policeman.
Towards the thin stream of light flowing, as it seemed, from under the door, Mulligan took his cautious way. Knocking softly, he waited. No reply came. Again he knocked, and again the silence which struck a chill to his heart ensued. At length he took his courage in both hands and flung open the door. It was not locked. A gush of light nearly blinded him. He staggered back, and placed his hands across his dazzled eyes. Then he looked in bewilderment at a remarkable scene. The room was square and rather large, unbroken by pillar or arch, and contained only one window. Walls and roof and flooring and furniture and hangings were absolutely white. There was not a spot or speck of colour in the place. The walls were of white enamel studded with silver fleur-de-lis; the floor of polished marble strewn with white skins of long-haired animals. The curtains, drawn aside from the window, were of milky velvet. The furniture was of white polished wood cushioned with pearly silks. Everywhere the room was like snow, and the milky globes of the lamps shed an argent radiance over the whole. It looked cold and cheerless but eminently beautiful. An artistic room, but not one that had a homely look about it. The white glow, the dazzling expanse, colourless and severe, made the man shiver, rough though he was. "It's like a cold winter's day," said the imaginative Celt.
Suddenly he uttered an exclamation. On moving cautiously into the room, he saw a piano of polished white wood in a recess, concealed by a white velvet curtain from the door. Before the piano lay a white bearskin; on this, face downward; the body of a woman. She was dressed in black, the one spot of colour in that pale room. But there was another colour--a vivid red, staining the skin. Mulligan touched the body--it was cold and limp. "Dead," said Mulligan. From under the left shoulder-blade trickled a thin stream of blood, and his voice, strong as it was, used as he had been to scenes of terror, faltered in the dead silence of that death-chamber.
"Dead! Murdered!"
Not a sound. Even the wind had died away. Only the strong man looking down at that still corpse, only the blackness of her dress; the redness of her life-blood soaking into the white bearskin, and all around the wan desolation of that white, mysterious room, Arctic and silent.
CHAPTER II
ANOTHER MYSTERY
Mulligan stared at the dead woman, but beyond touching her to see if life remained, he did not attempt to alter the position of the corpse. For corpse it was. The woman was as dead as a stone, and Mulligan knew his duty too well to take any authority upon himself The inspector was the man to issue orders, and the inspector would be at the head of Achilles Avenue when the clock struck twelve. As this thought passed slowly through the policeman's mind--for the unexpectedness of the tragedy had somewhat dazed him--he heard the midnight chimes. With a sudden start he recovered his wits and wheeled round. In a few minutes he was out of the house, and had closed the door. Only when in the roadway did his brain begin to work at its normal speed.
"It's that young gentleman," thought Mulligan. "He said I'd come across a crime sooner than I expected. And the key is his. Mary, be good to us; but he must have killed the poor creature before he joined me. Augh!" He stopped and considered. "But if that's so, what about the singing. She was at the piano, and the song wasn't done when the gentleman joined me. Augh!"
At this moment of his reflection, and while he was looking anxiously down the road for the inspector, a man came walking rapidly along, and suddenly emerged from a side-street that ran at right angles to Achilles Avenue. He almost dashed into the arms of Mulligan, who brought up short under a lamp. "Where are ye going?" asked the policeman, rendered suspicious by his recent discovery and by the manifest haste of the man.
"Going, confound you!" snapped the man, who seemed to be in a very bad temper. "I'm looking for my motor-car."
"For your what?"
"Motor-car! Automobile! Can't you understand English? I've lost it. Some one's bolted with the whole kit. Have you seen my car? It's painted yellow picked out with black, and------"
"Here's the inspector," chipped in Mulligan, recognising with relief the rigid form of his superior. "You can tell him, and if you're the man, anything you may say will be used in evidence against you. That's the law. Augh!"
The man stared at this speech, but Mulligan wiped his heated brow and glared at him in a resentful manner, not at all sure but what this might be the criminal. There was no ground for such a supposition, especially as the key belonged to another man. But Mulligan was not in a position to weigh his words, and therefore said the first thing that came into his mind. So the man stared, Mulligan scowled, and the inspector drew near.
"You've been drinking, bobby," said the man at length. "My name is Luther Tracey. I manufacture motor-cars, and some beast has bolted with one of the best I've ever turned out. Such a flier. I guess you police hereabouts ain't worth a cent."
"You're American," said Mulligan.
"And you're several kinds of ass, I reckon. See here, about this car of mine."
Mr. Tracey would
