Although I had met with an unforeseen check, I had nevertheless learned three things. I had learned that Miguel the quadroon was possibly in league with the Hindu; that the Hindu was called Chunda Lal; and that Chunda Lal received messages, probably instructions, from a third party who announced his presence by the word "Scorpion."  
One of my fellows, of course, had been in the cafe all the evening, and from him I obtained confirmation of the fact that it had been the Hindu who had been summoned to the telephone and whom I had heard speaking. Instant upon the man at the cafe replacing the telephone and disconnecting, I called up the exchange. They had been warned and were in readiness.
 
"From what subscriber did that call come?" I demanded.
 
Alas! another check awaited me. It had originated in a public call office, and "Scorpion" was untraceable by this means!
 
Despair is not permitted by the traditions of the Service de Surete. Therefore I returned to my flat and recorded the facts of the matter thus far established. I perceived that I had to deal, not with a designing woman, but with some shadowy being of whom she was an instrument. The anomaly of her life was in a measure explained. She sojourned in Paris for a purpose—a mysterious purpose which was concerned (I could not doubt it) with the Grand Duke Ivan. This was not an amorous but a political intrigue.
 
I communicated, at a late hour, with the senior of the three men watching the Grand Duke. The Grand Duke that evening had sent a handsome piece of jewellery purchased in Rue de la Paix to the dancer. It had been returned.
 
In the morning I met with the good Casimir at his favorite cafe. He had just discovered that Zara el-Khala drove daily to the Bois de Boulogne, alone, and that afternoon the Grand Duke had determined to accost her during her solitary walk. I prepared myself for this event. Arrayed in a workman's blouse and having a modest luncheon and a small bottle of wine in a basket, I concealed myself in that part of the Bois which was the favourite recreation ground of the dancer, and awaited her appearance.
 
The Grand Duke appeared first upon the scene, accompanied by Casimir. The latter pointed out to him a path through the trees along which Zara el-Khala habitually strolled and showed him the point at which she usually rejoined the Hindu who followed along the road with the car. They retired. I seated myself beneath a tree from whence I could watch the path and the road and began to partake of the repast which I had brought with me.
 
At about three o'clock the dancer's car appeared, and the girl, veiled as usual, stepped out, and having exchanged a few words with the Indian, began to walk slowly towards me, sometimes pausing to watch a bird in the boughs above her and sometimes to examine some wild plant growing beside the way. I ate cheese from the point of a clasp-knife and drank wine out of the bottle.
 
Suddenly she saw me.
 
She had cast her veil aside in order to enjoy the cool and fragrant air, and as she stopped and regarded me doubtfully where I sat, I saw her beautiful face, undefiled, now, by make-up and unspoiled by the presence of garish Eastern ornaments. Nom d'un nom! but she was truly a lovely woman! My heart went out in sympathy to the poor Grand Duke. Had I received such a mark of favour from her as he had received, and had I then been scorned as now she scorned him, I should have been desperate indeed.
 
Coming around a bend in the path, then, she stood only a few paces away, looking at me. I touched the peak of my cap.
 
"Good-day, mademoiselle," I said. "The weather is very beautiful."
 
"Good-day," she replied.
 
I continued to eat cheese, and reassured she walked on past me. Twenty yards beyond, the Grand Duke was waiting. As I laid down my knife upon the paper which had been wrapped around the bread and cheese, and raised the bottle to my lips, the enamoured nobleman stepped out from the trees and bowed low before Zara el-Khala.
 
She started back from him—a movement of inimitable grace, like that of a startled gazelle. And even before I had time to get upon my feet she had raised a little silver whistle to her lips and blown a short shrill note.
 
The Grand Duke, endeavouring to seize her hand, was pouring out voluble expressions of adoration in execrable French, and Zara el-Khala was retreating step by step. She had quickly thrown the veil about her again. I heard the pad of swiftly running feet. If I was to intervene before the arrival of the Hindu, I must act rapidly. I raced along the path and thrust myself between the Grand Duke and the girl.
 
"Mademoiselle," I said, "is this gentleman annoying you?"
 
"How dare you, low pig!" cried the Grand Duke, and with a sweep of his powerful arm he hurled me aside.
 
"Thank you," replied Zara el-Khala with great composure. "But my servant is here."
 
As I turned, Chunda Lal hurled himself upon the Grand Duke from behind. I had never seen an expression in a man's eyes like that in the eyes of the Hindu at this moment. They blazed like the eyes of a tiger, and his teeth were bared in a savage grin which I cannot hope to describe. His lean body seemed to shoot through the air, and he descended upon his burly adversary as a jungle beast falls upon its prey. Those long brown fingers clasping his neck, the Grand Duke fell forward upon his face.
 
"Chunda Lal!" said the dancer.
 
Kneeling, his right knee thrust between the shoulder blades of the prostrate man, the Hindu looked up—and I read murder in those glaring eyes. That he was an accomplished wrestler—or perhaps a strangler—I divined from the helplessness of the Grand ............