d eye. However, it disappeared immediately
afterwards."

"Well, what made you believe the other plane was watching us?"
inquired Bob.

Frank laughed in half-embarrassed fashion.

"Oh, one of my hunches," he said.

His two chums grinned understandingly at each other. It was a
recognized fact among them that Frank was super-sensitive and
frequently, as a result, received sharp impressions concerning people
and events which were unsupported by evidence at the time, but which
later proved to be correct. Frank was the slightest of the trio, of
only medium height but wiry build, while Bob and Jack both were six
feet tall and Bob, besides, had a broad and powerful frame.

"Seeing spooks again?" chaffed Bob.

Immediately, they became more serious as Frank, ignoring the banter,
leaned forward and made his proposal:

"That plane landed, and I believe it landed at Starfish Cove. Let's
fly back and take a look. See what's it like, at any rate."

"Good idea," approved Jack.

Bob had been taxying about slowly since landing, in order to keep the
engine going and the propeller slowly revolving. Now he picked up
speed, straightened out, shifted the lifting plane, and the machine
shot forward, skirled over the water and presently took the air.

For some minutes they flew in silence, at no great height, and a
little distance out from the coast. Bob's attention was devoted to the
plane, but Frank and Jack scanned the shore with eager eyes. Presently
they saw what they were looking for. A strange plane rode in the lazy
swell offshore in Starfish Cove. There was nobody aboard. Not a soul
was in sight on land. The little stretch of sandy beach, between the
two horns of the cove, stretched untenanted back to the thick fringe
of trees.

Bob swooped so low the plane almost skimmed the water, and all three
obtained a good view of the stranger, before once more Bob soared
aloft and forged ahead. Looking back, Frank trained the glasses on the
scene. But nobody appeared from among the trees, and, far as they
could determine, they were unobserved.

They made a quick run to their own landing field, descended and put
the plane away. Not until the doors were closed and locked did they
sit down on the skidway outside the hangar to discuss what they had
seen. There had been remarks made by all after they had seen the
strange plane at close range and on the hasty trip home, but all had
been too busy with their own thoughts for extended disc