"I wonder if it's night yet," said Mary, for it was impossible to tell in the dark cave. The girls had Andy's torch, for no daylight came into the cave at all. They crept to the shore-cave to see. Yes—it was twilight outside. Night would soon fall.
"I vote we make a nice soft bed in the sandy floor," said Jill. "We can cover ourselves with those empty sacks. And in the morning we'll peep out and see if we can see anything!"
So they made sandy beds and threw the sacks over themselves, they fell fast asleep and did not wake till morning.
And then, when they went to peep out of the shore-cave, they had a great surprise! Coming gracefully down to the smooth water was an enormous seaplane, droning like a great bumble-bee.
"It's coming to get us!" squealed Mary in fright, and the two girls scuttled back into the Round Cave!
Chapter 25
Return to the Islands
If only the girls had stopped to look carefully at that seaplane, they would have noticed that it bore the signs of their own country! It was the very same seaplane that had rescued Tom and Andy! It had flown to headquarters, had made its report, and had handed Tom's camera in. As soon as the pictures had been developed, and the seaplane and submarine photographs had come out clearly, there was great excitement.
Tom and Andy had been questioned closely They told their story clearly and well, and the men who listened to them were amazed at the adventures the four children had been through.
"Well, you have stumbled on an astonishing secret," said one man who had been listening, "We are proud of you! Now we shall be able to spring a real surprise on our enemy, and clean up all the submarines and seaplanes that have been worrying our shipping for some time. We did not know they had a base so near us. No wonder they have been able to do such damage!"