Mother Flintstone was reputed rich; she was said to have accumulated by her calling a good deal of wealth, which she had concealed somewhere, but where even Billy, her one little confidant, did not know.

The boy looked at the face till it seemed to be photographed on his mind. He would know it among a thousand faces, he thought.

It should not escape him, and he would give a certain person a full description of it.

In a moment, as it were, the face vanished.

Billy turned again to the dead woman, but looked now and then toward the window. He saw that the old woman had been killed, for the rent in her throat told where the dagger had found her life and put an end to her varied career.

As yet the murder was his secret and the murderer’s.

Mulberry Billy remained in the little room some time, or until he had composed his nerves.

One does not discover a terrible crime every day, not even in New York. He wanted to think the matter over a little; he wanted to decide just what to do.

“I’ll see Patsy again, that’s best,” he said aloud, though addressing himself. “Patsy Garvan once befriended me, and he’ll tell Mr. Carter about this, and I know Mr. Carter’s the man to take charge of this matter and avenge Mother Flintstone.”

With this the street Arab slipped from the house and went out upon the street again.