"The Jersey fellow says there is nothing between his lens and your plane to obstruct the view."
"O.K.," retorted Jeter. "At the moment your buzzer sounded our plane suddenly jumped upward. That means an upcurrent of air indicating an obstruction under us. It must however, be invisible."
He severed the connection. His brow was furrowed thoughtfully. He was remembering Sitsumi and his rumored discovery.
They circled back warily. The eyes of both were fixed downward, staring into space. Their jaws were firmly set. Their eyes were narrowed.
And then....
There was that uprush of air again! It appeared to rise from an angle of about sixty degrees. They got the wind against their nose and started a humming dive, feeling in the alien updraft for the obstruction which caused it.
CHAPTER VII
Invisible Globe
The buzzer of their radiophone was sounding, but so intent were they on this phenomenon they were facing, they paid it no heed. Their eyes were alight, their lips in firm straight lines of resolve, as they dived down upon the invisible obstruction—whatever it was—from whose surface the telltale updraft came.