Brent could only stare open-mouthed as the black figure swept by him and was lost in the crowds. Surprised by the entire action, he turned back to find Di Costa staring directly into his eyes!

Whatever course of action he might have considered was lost. Di Costa took the initiative. He smiled and waved. Brent could hear his voice faintly through the street noises.

“ Mr. Dalgreen, over here!”

Brent waved back and did the only thing possible. As he walked slowly forward he saw that Di Costa’s curiosity had gotten the better of him. Brent watched him open the note, read it⁠—and change suddenly. The man’s arm dropped to his side, his body stiffened. Staring straight ahead, he stood on the walkway, eyes fixed and as full as a Roman portrait bust.

Dalgreen hurried toward the man. Events were going too fast. He had more than a suspicion that the note and the short man were somehow connected with the secret of the paintings. He stepped forward.

The man stared ahead, unseeing and unhearing. Brent felt justified in removing the mysterious note from between his fingers. One side was blank, but the other contained a single illegible character⁠—queer sign made up of flowing curves crossed by choppy green lines. It resembled nothing Brent had ever seen in his entire life.

They rode uptown side by side. Brent leaned on the railing while Di Costa remained fixed in his strange trance. The note in Brent’s hand was tangible evidence that his suspicions had some basis in fact. As he examined it again, he was aware of an undefinable tingling in his hand. The note seemed to be vibrating, shaking free from his hand in some unknown way. Under his startled gaze it glowed suddenly and disappeared! One instant he had held it, the next his hand was empty.