"Then that's why you came out from England in a hurry, eh?" he murmured. "The Japs are actually going to be saps, huh?"

The Air Intelligence officer smiled faintly at Dawson's remark, but shook his head and raised a cautioning finger.

"That is the spirit, Dawson," he said, "but don't be carried away by the belief that the Japs would ... would be push-overs, as they say in your country. As a matter of fact, the one mistake we have made most in this blasted war, and during the years leading up to it, too, has been to underestimate the strength and ability of the enemy. The Japs may be saps, as you say, but that won't stop them from attacking if they think they hold the winning hand. And I'm afraid they do believe they hold it."

"But they would be bashing their crazy heads against a stone wall!" Freddy Farmer protested. "I mean if they dared to have a go at Singapore. I've always been told that Singapore is every bit as impregnable as Gibraltar."

"From sea attack, yes," Air Vice Marshal Bostworth said. "But from the air? That is something else again. And as far as Singapore is concerned, the greatest weakness in its defense is not on the Island at all."

"Not on the Island, sir?" Dave Dawson echoed. "I don't think I get you."

"The water supply," the senior officer said. "It comes from Johore on the mainland side of the Strait, and is piped over the causeway. Blast Singapore's water supply and the lads on the Island would have a pretty bad time of it. However, that's neither here nor there for the moment. Dawson, you asked just a moment ago why didn't some other plane pick you up before this one. I'll tell you. Because there weren't any other planes in the air. I recalled all patrols early this morning, and grounded all planes."

The Air Vice Marshal paused for a moment, and although a thousand questions hovered on the boys' lips, they knew enough to hold their tongues.

"It's hard to tell the story," Bostworth continued presently with a frown, "because there are so many parts of it that we don't know a thing about. In a nutshell, it's this. Everything we do out here is known in detail in Berlin, Rome, and Tokio within a few hours. The blighters couldn't be better informed if we broadcast every move we make over the radio. They are finding out everything, worse luck. That was why I was sent out here. To find the leak, or leaks, and plug 'em up. As you both know, the population of Singapore is as mixed in nationalities as any other spot in the whole world. I'll wager that you could find a man from every country in the world within the limits of Singapore. Not only is it a great naval base of England's, it is also one of the great trading ports of the world. And you can be very sure that the city, itself, and the waterfront, is a thriving place for spies, right now more than ever before."

The senior officer paused for breath and stared thoughtfully out one of the portholes. The Catalina was still climbing steadily, but it had not reached an altitude where it was necessary to reach for the small portable oxygen kits fitted to the wall.