"Ten shillings says you've forgotten there's lots of radios in England, Dawson!" Flight Lieutenant Barker snapped back at him in the earphones.

Dave gulped and went beet red to the roots of his hair. In his excitement he had clean forgotten that ground stations are tuned in on aircraft aloft all the time. Whatever is said up there goes right into the ears of the big shots, if they happen to be listening.

"I mean when the formation reaches the objective!" Dave said hurriedly. "One Mark Five is more than enough for any One-Ten!"

Barker's laugh came over the radio.

"That's nice quick thinking, Dawson," he said. "No wonder you've got more than a couple of the beggars in your bag."

"Luck! Absolutely nothing else. I was present each time!"

The voice was Freddy Farmer's. Dave opened his mouth to make a fitting retort, but checked himself. At that instant he heard the voice of the Operations officer back down on the field.

"Tiger Flight!" he called, using the code name for the patrol in the air. "Change course twenty degrees north. Clouds ahead of you. Enemy aircraft climbing to twenty-four thousand. Operations to Tiger. That is all!"

"Tiger to Operations!" Dave heard Flight Lieutenant Barker check back. "Changing course. Right you are!"

Dave had already swung his ship around more to the north, and was hunched forward over the stick staring hard at the mountain cloud bank looming up ahead. His eagle eyes swept it from side to side and from top to bottom. But he failed to see a single moving dot that could be the Messerschmitt One-Ten trying to climb up over the stuff. He saw nothing but that bank of clouds and the crazy shadows that marked nature's nooks and crags in the stuff.