At last, half-way up the next block, even as his lungs filled for another peal, he thought his eyes caught for a short half-second the mere thin shadow of a skulking figure.  It had seemed to pass through a grape arbour that all but shielded from the street a house slightly more pretentious than its neighbours.  He ran toward the spot, calling as he went.  But when he had vaulted over the low fence, run across the garden and around the end of the arbour, dense with the green leaves and clusters of purple grapes, the space in front of the house was bare.  If more than a trick-phantom of his eye had been there, it had vanished.

He stood gazing blankly at the front door of the house.  Was it fancy that he had heard it shut a second before he came? that his nerves still responded to the shock of its closing?  He had already imagined so many noises of the kind, so many misty shapes fleeing before him with little soft rustlings, so many whispers at his back and hushed cries behind the closed doors.  Yet this door had seemed to shut more tangibly, with a warmer promise of life.  He went quickly up the three wooden steps, turned the knob, and pushed it open—­very softly this time.  No one appeared.  But, as he stood on the threshold, while the pupils of his eyes dilated to the gloom of the hall into which he looked, his ears seemed to detect somewhere in the house a muffled footfall and the sound of another door closed softly.

He stepped inside and called.  There was no answer, but above his head a board creaked.  He started up the stairs in front of him, and, as he did so, he seemed to hear cautious steps across a bare floor above.  He stopped climbing; the steps ceased.  He started up, and the steps came again.  He knew now they came from a room at the head of the stairs.  He bounded up the remaining steps and pushed open the door with a loud “Halloo!”

The room was empty.  Yet across it there was the indefinable trail of a presence,—­an odour, a vibration, he knew not what,—­and where a bar of sunlight cut the gloom under a half-raised curtain, he saw the motes in the air all astir.  Opposite the door he had opened was another, leading, apparently, to a room at the back of the house.  From behind it, he could have sworn came the sounds of a stealthily moved body and softened breathing.  A presence, unseen but felt, was all about.  Not without effort did he conquer the impulse to look behind him at every breath.

Determined to be no longer eluded, he crossed the room on tiptoe and gently tried the opposite door.  It was locked.  As he leaned against it, almost in a terror of suspense, he knew he heard again those little seemings of a presence a door’s thickness away.  He did not hesitate.  Still holding the turned knob in his hand, he quickly crouched back and brought his flexed shoulder heavily against the door.  It flew open with a breaking sound, and, with a little gasp of triumph, he was in the room to confront its unknown occupant.