Then, suddenly, her whole body became tense. The hand holding the bottle flew back. It shot forward.

CHAPTER VII
THE MYSTERY DEEPENS

When they saw Marian’s hand go back for the throw, the two other girls, their fear overcome by curiosity, sprang silently to a position beside their companion.

What they saw made them draw back in fright. Two rounds of a ladder extended above the outer rim of the boat. Above the last round appeared a face. This face, though almost completely hidden by a heavy muffler, was undoubtedly that of a man.

Before they had time to move, however, they saw the bottle of liquid gas strike the top rail and burst. The liquid spattering over the man’s face and clothing, brought forth a sharp exclamation. The next instant, seeming to struggle against an invisible foe, he made desperate attempts to dismount from his lofty position. In this he was partially successful. He disappeared from sight. But the next moment there came the thud of a falling body. The ladder was still in position. The three girls held their breath.

“He fell,” said Lucile in a tremulous whisper.

“I only hope he—”

“No you don’t!” Lucile interrupted. “No one wishes a person seriously injured.” Lucile shuddered.

“Well, anyway he wasn’t,” said Florence, “for there he is. The gas is working splendidly.”

The man was dancing about below, swinging his arms and shouting madly.