Deep in thought respecting the inexplicable nature of this latest mystery, I turned in the direction of the bridge, and leaving behind me an ever-swelling throng at the gate of Wyatt's Buildings, proceeded westward.  
The death of the dwarf had lifted the case into the realms of the marvellous, and I noted nothing of the bustle about me, for mentally I was still surveying that hunched-up body which had fallen out of empty space.
 
Then in upon my preoccupation burst a woman's scream!
 
I aroused myself from reverie, looking about to right and left. Evidently I had been walking slowly, for I was less than a hundred yards from Wyatt's Buildings, and hard by the entrance to an uninviting alley from which I thought the scream had proceeded.
 
And as I hesitated, for I had no desire to become involved in a drunken brawl, again came the shrill scream: "Help! help!"
 
I cannot say if I was the only passer-by who heard the cry; certainly I was the only one who responded to it. I ran down the narrow street, which was practically deserted, and heard windows thrown up as I passed for the cries for help continued.
 
Just beyond a patch of light cast by a street lamp a scene was being enacted strange enough at any time and in any place, but doubly singular at that hour of the night, or early morning, in a lane off the Waterloo Road.
 
An old woman, from whose hand a basket of provisions had fallen, was struggling in the grasp of a tall Oriental! He was evidently trying to stifle her screams and at the same time to pinion her arms behind her!
 
I perceived that there was more in this scene than met the eye. Oriental footpads are rarities in the purlieus of Waterloo Road. So much was evident; and since I carried a short, sharp argument in my pocket, I hastened to advance it.
 
At the sight of the gleaming revolver barrel the man, who was dressed in dark clothes and wore a turban, turned and ran swiftly off. I had scarce a glimpse of his pallid brown face ere he was gone, nor did the thought of pursuit enter my mind. I turned to the old woman, who was dressed in shabby black and who was rearranging her thick veil in an oddly composed manner, considering the nature of the adventure that had befallen her.
 
She picked up her basket, and turned away. Needless to say I was rather shocked at her callous ingratitude, for she offered no word of thanks, did not even glance in my direction, but made off hurriedly toward Waterloo Road.
 
I had been on the point of inquiring if she had sustained any injury, but I checked the words and stood looking after her in blank wonderment. Then my ideas were diverted into a new channel. I perceived, as she passed under an adjacent lamp, that her basket contained provisions such as a woman of her appearance would scarcely be expected to purchase. I noted a bottle of wine, a chicken, and a large melon.
 
The nationality of the assailant from the first had marked the affair for no ordinary one, and now a hazy notion of what lay behind all this began to come to me.
 
Keeping well in the shadows on the opposite side of the way, I followed the woman with the basket. The lane was quite deserted; for, the disturbance over, those few residents who had raised their windows had promptly lowered them again. She came out into Waterloo Road, crossed over, and stood waiting by a stopping-place for electric cars. I saw her arranging a cloth over her basket in such a way as effectually to conceal the contents. A strong mental excitement possessed me. The detective fever claims us all at one time or another, I think, and I had good reason for pursuing any inquiry that promised to lead to the elucidation of the slipper mystery. A theory, covering all the facts of the assault incident, now presented itself, and I stood back in the shadow, watchful; in a degree, exultant.
 
A Greenwich-bound car was hailed by the woman with the basket. I could not be mistaken, I felt sure, in my belief that she cast furtive glances about her as she mounted the steps. But, having seen her actually aboard, my attention became elsewhere engaged.
 
All now depended upon securing a cab before the tram car had passed from view!
 
I counted it an act of Providence that a disengaged taxi appeared at that moment, evidently bound for Waterloo Station. I ran out into the road with cane upraised.
 
As the man drew up—
 
"Quick!" I cried. "You see that Greenwich car—nearly at the Ophthalmic Hospital? Follow it. Don't get too near. I will give you further instructions through the tube." I leapt in. We were off!
 
The rocking car ahead was rounding the bend now toward St. George's Circus. As it passed the clock and entered South London Road it stopped. I raised the tube.
 
"Pass it slowly!"
 
We skirted the clock tower, and bore around to the right. Then I drew well back in the corner of the cab.
 
The woman with the basket was descending! "Pull up a few yards beyond!" I directed. As the car re-started, and passed us, the taxi became stationary. I peered out of the little window at the back.
 
The woman was returning in the direction of Waterloo Road!
 
"Drive slowly back along Waterloo Road," was my next order. "Pretend you are looking for a fare; I will keep out of sight."
 
The man nodded. It was unlikely that any one would notice the fact that the cab was engaged.
 
I was borne back again upon my course. The woman kept to the right, and, once we were entered into the straight road which leads to the bridge, I again raised the speaking-tube.
 
"Pull up," I said. "On the right-hand side is an old woman carrying a basket, fifty yards ahead. Do you see her? Keep well behind, but don't lose sight of her."
 
The man drew up again and sat watching the figure with the basket until it was almost lost from sight. Then slowly we resumed our way. I would have continued the pursuit afoot now, but I feared that my quarry might again enter a vehicle. She did not do so, however, but coming abreast of the turning in which the mysterious assault had taken place, she crossed the road and disappeared from view.
 
I leapt out of the cab, thrust half a crown into the man's hand, and ran on to the corner. The night was now far advanced, and I knew that the chances of detection were thereby increased. But the woman seemed to have abandoned her fears, and I saw her just ahead of me walking resolutely past the lamp beyond which a short time earlier she had met with a dangerous adventure.
 
Since the opposite side of the street was comparatively in darkness, I slipped across, and in a state of high nervous tension pursued this strange work of espionage. I was convinced that I had forestalled Bristol and that I was hot upon the track of those who could explain the mystery of the dead dwarf.
 
The woman entered the gate of the block of dwellings even more forbidding in appearance than those which that night had staged a dreadful drama.
 
As the figure with the basket was lost from view I crept on, and in turn entered the evil-smelling hallway. I stepped cautiously, and standing beneath a gaslight protected by a wire frame, I congratulated myself upon having reached that point of vantage as silently as any Sioux stalker.
 
Footsteps were receding up the stone stairs. Craning my neck, I peered up the well of the staircase. I could not see the woman, but from the sound of her tread it was possible to count the landings which she passed. When she had reached the fourth, and I heard her step upon yet another flight, I knew that she must be bound for the topmost floor; and observing every precaution, almost holding my breath in a nervous endeavour to make not the slightest sound, rapidly I mounted the stairs.
 
I was come to the third landing in this secret fashion when quite distinctly I heard the grating of a key in a lock!
 
Since four doors opened upon each of the landings, at all costs, I thought, I must learn by which door she entered.
 
Throwing caution to the winds I raced up the remaining flights ... and there at the top the woman confronted me, with blazing eyes!—with eyes that thrilled every nerve; for they were violet eyes, the only truly violet eyes I have ever seen! They were the eyes of the woman who like a charming, mocking will-o'-the-wisp had danced through this tragic scene from the time that poor Professor Deeping had brought the Prophet's slipper to London up to this present hour!
 
............