"Even the Black Star can't make himself invisible at will!"
Then they heard the Black Star laugh derisively.
They flashed their torches and again searched the roof. Once more they heard the laugh. Now it seemed to be to one side of them, and now to another. Above them, behind them, in front of them they heard it.
"This thing will drive me crazy!" the chief cried. "Flash those torches again! That crook is somewhere right here on the roof! Look for another trapdoor!"
They searched the roof, and found nothing; but again they heard the laugh, only it sounded far away now. Suddenly the roof was bathed in bright light that seemed to come out of the sky.
"He's up there—on something!" the chief shrieked.
They emptied their revolvers and automatics toward the sky. The light died out, flashed forth again and almost blinded them. Once more they heard the sarcastic laugh of the Black Star, as if far in the distance—and then the light was gone.
They stood silent, looking upward. Not the slightest sound came to their ears, except echoes of the shouts in the street below, where people were wondering about the peculiar, blinding light.
"What does it mean?" the chief cried. "Verbeck, what has that devil done?"
"I haven't the faintest idea," Roger Verbeck replied. "I don't understand that laugh, and I can't imagine where that light comes from. I'd think naturally, that it was an airplane, but, as you said, it would be almost impossible to pick a man off
