"What is the poison?" I asked.

"Curari," he replied simply. "It acts on the respiratory muscles, paralyzing them, and causing asphyxiation."

The dart seemed to have been made of a quill with a very sharp point, hollow, and containing the deadly poison in the sharpened end.

"Look out!" I cautioned as he handled it.

"Oh, that's all right," he answered casually. "If I don't scratch myself, I am safe enough. I could swallow the stuff and it wouldn't hurt me—unless I had an abrasion of the lips or some internal cut."

Kennedy continued to examine the dart until suddenly I heard a low exclamation of surprise from him. Inside the hollow quill was a thin sheet of tissue paper, tightly rolled. He drew it out and read:

"To know me is DEATH Kennedy—Take Warning!"

Underneath was the inevitable Clutching Hand sign.

We jumped to our feet. Kennedy rushed to the window and slammed it shut, while I seized the key from Michael's pocket, opened the door and called for help.

A moment before, on the roof of a building across the street, one might have seen a bent, skulking figure. His face was copper colored and on his head was a thick thatch of matted hair. He looked like a South American Indian, in a very dilapidated suit of castoff American clothes.