surprise attack. Not only were
the flights in echelon, but the planes of each unit were also echeloned,
each plane being slightly above the one directly ahead. It was a
formidable formation, capable of being readily manoeuvered and with each
pilot insured the best possible vision.

A few white, vapory clouds hung high over the trenches toward Comblizy,
and still heavier banks were to be seen to the south of la Chapelle,
hanging over the Surmelin Valley. In all other directions the sky
presented that fathomless blue so well known to all pilots who ascend
above ten thousand feet. The open space between these apparently
unmoving cloud banks was some three or four miles in width.

Larkin, in the top flight with Major Cowan, had taken up position as the
hindermost plane in the group and had, therefore, the greatest altitude.
As a rule, he never was satisfied with his altitude until he had pushed
his plane somewhere near the limit of its climbing ability. He was a
splendid pilot at great altitude, and he had learned from experience
that many pilots capable of doing good work at the lower levels flounder
around like fish out of water when above twelve thousand feet. This
being equally true of friend and foe, Larkin always felt better when he
was high enough not to have any worry about someone coming down on him.
He preferred having his enemies below rather than above.

This morning, however, he took no thought of the matter. Before taking
off Major Cowan had said no more than, "Look sharp when we get south of
la Chapelle; head on a pivot, you know." Shucks! Slim chance for any
excitement with a group like this. Even if they sighted a small enemy
patrol they would have to go merrily on their way and leave the game to
someone else. However, a war pilot with skill enough to become such an
ace as Larkin needs little caution about "looking sharp." It is habit
with him, and those who fail to develop the habit are only a few hours
or days removed from sudden disaster.

There was little enough to see. They were flying westward. Again and
again Larkin turned his head around, closed one eye and placing a thumb
close to his open eye squinted into the blinding sun. Many times, by the
employment of that little trick, he had been able to momentarily diffuse
the sun's rays sufficiently to catch the faintest blurred outline of
enemy planes sitting in the sun and waiting for the proper moment to
dive.

This morning the sun seemed unusual