He glanced at his watch. Stuart was standing by the lofty window looking out across the Embankment. "Ten o'clock," said Dunbar. "The Commissioner will be expecting us." "I am ready," responded Stuart. Leaving Sergeant Sowerby seated at the table studying the note-book, Stuart and Dunbar proceeded to the smoke-laden room of the Assistant Commissioner. The great man, suavely satanic, greeted Stuart with that polished courtesy for which he was notable. "You have been of inestimable assistance to us in the past, Dr. Stuart," he said, "and I feel happy to know that we are to enjoy the aid of your special knowledge in the present case. Will you smoke one of my cigarettes? They are some which a friend is kind enough to supply to me direct from Cairo, and are really quite good." "Thanks," replied Stuart. "May I ask in what direction my services are likely to prove available?" The Commissioner lighted a fresh cigarette. Then from a heap of correspondence he selected a long report typed upon blue foolscap. "I have here," he said, "confirmation of the telegraphic report received last night. The name of M. Gaston Max will no doubt be familiar to you?" Stuart nodded. "Well," continued the Commissioner, "it appears that he has been engaged in England for the past month endeavouring to trace the connection which he claims to exist between the sudden deaths of various notable people, recently--a list is appended--and some person or organisation represented by, or associated with, a scorpion. His personal theory not being available--poor fellow, you have heard of his tragic death--I have this morning consulted such particulars as I could obtain respecting these cases. If they were really cases of assassination, some obscure poison was the only mode of death that could possibly have been employed. Do you follow me?" "Perfectly." "Now, the death of Gaston Max under circumstances not yet explained, would seem to indicate that his theory was a sound one. In other words, I am disposed to believe that he himself represents the most recent outrage of what we will call 'The Scorpion.' Even at the time that the body of the man found by the River Police had not been identified, the presence upon his person of a fragment of gold strongly resembling the tail of a scorpion prompted me to instruct Inspector Dunbar to consult you. I had determined upon a certain course. The identification of the dead man with Gaston Max merely strengthens my determination and enhances the likelihood of my idea being a sound one." He flicked the ash from his cigarette and resumed: