“Lounge up and down outside, Petrie.  Everyone has cleared off now.  It is getting late.  Keep your eyes open and be on your guard.  I thought I had the start, but he is here before me, and, what is worse, he probably knows by now that I am here, too.”

With which he entered the house and left me out in the square, with leisure to think, to try to understand.

The crowd which usually haunts the scene of a sensational crime had been cleared away, and it had been circulated that Sir Crichton had died from natural causes.  The intense heat having driven most of the residents out of town, practically I had the square to myself, and I gave myself up to a brief consideration of the mystery in which I so suddenly had found myself involved.

By what agency had Sir Crichton met his death?  Did Nayland Smith know?  I rather suspected that he did.  What was the hidden significance of the perfumed envelope?  Who was that mysterious personage whom Smith so evidently dreaded, who had attempted his life, who, presumably, had murdered Sir Crichton?  Sir Crichton Davey, during the time that he had held office in India, and during his long term of service at home, had earned the good will of all, British and native alike.  Who was his secret enemy?

Something touched me lightly on the shoulder.

I turned, with my heart fluttering like a child’s.  This night’s work had imposed a severe strain even upon my callous nerves.

A girl wrapped in a hooded opera-cloak stood at my elbow, and, as she glanced up at me, I thought that I never had seen a face so seductively lovely nor of so unusual a type.  With the skin of a perfect blonde, she had eyes and lashes as black as a Creole’s, which, together with her full red lips, told me that this beautiful stranger, whose touch had so startled me, was not a child of our northern shores.

“Forgive me,” she said, speaking with an odd, pretty accent, and laying a slim hand, with jeweled fingers, confidingly upon my arm, “if I startled you.  But—­is it true that Sir Crichton Davey has been—­murdered?”

I looked into her big, questioning eyes, a harsh suspicion laboring in my mind, but could read nothing in their mysterious depths—­ only I wondered anew at my questioner’s beauty.  The grotesque idea momentarily possessed me that, were the bloom of her red lips due to art and not to nature, their kiss would leave—­ though not indelibly—­just such a mark as I had seen upon the dead man’s hand.  But I dismissed the fantastic notion as bred of the night’s horrors, and worthy only of a mediaeval legend.  No doubt she was some friend or acquaintance of Sir Crichton who lived close by.

“I cannot say that he has been murdered,” I replied, acting upon the latter supposition, and seeking to tell her what she asked as gently as possible.

“But he is—­Dead?”

I nodded.

She closed her eyes and uttered a low, moaning sound, swaying dizzily.  Thinking she was about to swoon, I threw my arm round her shoulder to support her, but she smiled sadly, and pushed me gently away.