“It’s on,” she thought. “I’m sure I turned it off.”

This was strange for Nancy had been fast asleep when she turned in. Sally had tried picking up some sound of the “put-put-put-a-put” of the mysterious broadcasters and failed. Then she had—

At that her thoughts broke off short for, very faintly, because the radio was turned low, there came the familiar “put-put-put-put-a-put.”

“I turned the radio on in my sleep,” she told herself. There seemed to be no other possible conclusion, yet it seemed close to a miracle that she had done so for, during the two preceding days, she had caught not the faintest suggestion of a broadcast on her secret radio, and now, here, in the middle of the night, it was coming in strong. Needless to say, she listened with both her ears.

For two whole days she and Nancy, together with Riggs and the second radioman, had kept their convoy together, with blinker lights by night and flags by day. Not a sound had come from a radio on any ship of the convoy. It had been one of the strangest experiences of Sally’s entire life. To go to sleep at night after a look at dark bulks looming here and there on the horizon, and to wake up with those same ships in the identical position in regard to one another, yet some hundreds of miles on their way, had seemed unbelievable.

But now, here was the secret radio talking again. “This may be the hour,” she whispered excitedly as, having turned the dial, she listened once again.

Slipping from her berth, she drew on a heavy velvet dressing gown, turned the radio up a little, then sat there listening, turning a dial now and then, listening some more and all the time growing more excited.

After twenty minutes of listening her face took on a look of sheer horror.

“I can’t do it,” she thought. “I may be court-martialed. But I must! I must!”

For a full five minutes she sat there deep in perplexing thought. Having at last reached a decision, she went into action. After dressing hurriedly, she shut off the radio and disconnected its wires. Then, seizing it by the handle, she slipped out of the stateroom, glided along one passageway after another to wind up at last in the radio room where Lieutenant Riggs was standing watch alone.