A stirring round of applause announced the end of the act onstage. They came forward to take a bow and I ducked down, just in case they looked in my direction. The moment the curtains closed I slipped from my seat, down the side corridor, and out of the theater. It is always a shock to come out of a theater and find it is broad daylight outside, but it’s also a shock to emerge to find the weather completely changed. Whereas I had entered the theater to sultry, merciless sunlight, I came out to find heavy clouds had gathered overhead and odd breezes swirled to herald the arrival of a thunderstorm. I glanced nervously at the heavens. I hadn’t brought a brolly with me and quickened my pace toward the closest El station.

Now all I had to do was make my way back to Harlem and wait for Mr. Wilkie to come to me. But as I threaded my way through the busy crowd on the Bowery I realized that I was about to expound a preposterous theory and wondered if he’d believe me. What proof did I have, apart from a strong hunch? Surely many magicians’ assistants were willowy with long elegant fingers and I couldn’t really see her face because of the mask that covered her eyes.

Then suddenly I changed direction and darted across the street between a trolley car and a delivery cart. I did have proof. At my house, carefully wrapped in tissue paper, was a bloody cloth I had retrieved from the rubbish bin at the theater. I made up my mind to go home and to take the cloth to Daniel. He would probably be angry with me but I couldn’t afford to waste another minute before having that cloth tested. If it revealed that the substance wasn’t human blood at all but some kind of theatrical paint, then they’d take me seriously.