"We'll come with you," said the girls. But Andy shook his head.
"No," he said "From now oh, somebody must keep a watch on that seaplane. We must find out all we can. We will be back with you as soon as possible—but you must stay here and watch."
So the two girls were left behind whilst the boys ran across the island to take down their flapping signal.
"I don't know where in the world we should hide if we were discovered and hunted for," said Andy, rolling up the sail. "There isn't a single place here to hide away in—not a cave or anything."
Tom felt rather uncomfortable. He didn't want to be hunted for on that bare island! "I wish we could see how many men there are in that seaplane," he said, "and what they are doing, and everything."
"Where are your field-glasses?" asked Andy suddenly. "They would be just the thing to use. We could see everything as dearly as could be, then!"
"And my camera, too!" said Tom, jumping for joy. "What about my camera? We could take some photographs of the seaplane—then everyone would have to believe us when we get back—if ever we do get back!"
"That's a fine idea!" said Andy, really pleased. "Golly! If we could take some pictures of that seaplane with the crooked cross showing up clearly, there wouldn't be the least doubt of our story when we got home. Tom, let's go and get your glasses and your camera straight away."
They dumped the sail into a bush and ran to the shack. They took Tom's field-glasses and picked up the camera to see if it needed a new film. No—there was a new one inside.
"Better not use up all the film on the seaplane," said Andy. "There might be other interesting and extraordinary things to photograph—you never know!"