lot the data."

"Okay." Rick began with the first. "Five miles south of Wye Mills on
Route 50. Direction, southwest."

Scotty measured the distance from Wye Mills, using the map scale in
inches, then estimated the compass direction and drew a line. "Next."

Rick read on. By the time he had reached the tenth sighting, all three
of them were waiting anxiously for each new bit of data to be plotted.

Finally the job was complete. Steve had hurried off a moment before and
returned with a pair of compasses in his hand. As the boys watched, he
put the sharp point of one compass leg into a spot on the map, adjusted
the radius, and drew a perfect circle. He adjusted the radius again, and
drew a second circle, slightly larger, then a third.

"Bull's-eye!" Rick said excitedly.

The direction lines bisected the outer concentric circles like the radii
of an orb spider's web. In the center of the web was the smallest
circle. Within the circle was the focal point of all flying object
observations.

Rick said the name aloud.

"Swamp Creek!"

CHAPTER VIII

Calvert's Favor

There was a faint hint of coming daylight in the eastern sky when Rick,
Steve, and Scotty walked down the pier to the tied-up boats. The boys
had spent the night--or most of it--aboard the houseboat, until the
alarm pulled them from their sleeping bags at four o'clock. Steve had
breakfast cooking when they arrived at the farmhouse, and after coffee,
bacon, and eggs, they started on their mission.

"Daybreak is the lowest peak of daily activity," Steve said as they
climbed into the runabout. He took the pilot's seat, while Rick and
Scotty prepared to cast off.

"You might say that the first glimmer of daylight is man's worst hour,"
Steve continued. "It's the time when battles start, when planes take off
for dawn bombing runs. I've read that it's the time when most deaths
occur in hospitals, although I don't know for certain that it's true.
What's more important to us, it's the time of day when guards are most
sleepy and least alert."

The young agent had been working as he talked, checking the outboard
motor, checking the connections to the gasoline tank, and pumping
pressure into it. Now he pressed the starter and the well-kept motor
caught at once. Rick and Scotty cast off bow and stern lines and settled
themselves in the seat next to Steve.

"Unless this mysterious Mr. Merlin suffers from sleepless nights, he's
deep in slumber. The sound