uch on his shoulder, and the Happy Thought came to a dead
stop.

"Against orders, I know," said Jack, leaning forward and speaking under
his breath, "but look back there."

The dead pine-tree was still visible some four hundred yards away, but
there was something fluttering from one of its branches--a piece of red
flannel rag.

"A signal," said Fred, shortly, "and it means that somebody is after
us--after _that_," and he pointed to the express bag. "We've got to go
on, for some one is certainly behind us. We can't stay here and be
gobbled up, and a rabbit could hardly get through that laurel scrub.
Besides, there's just a chance that it doesn't mean anything, after all.
We'll run ahead carefully, and if it comes to the worst, we'll cut
everything loose and make a dash for it. There's nothing short of a
rifle-bullet that can catch us."

"Let her go," returned Jack, briefly.

A quarter of a mile further, and the boys began to breathe easier. They
were on Breakneck Hill now, and there was nothing suspicious in the look
ahead. Half-way down, and as they swung around a curve Fred's heart
suddenly seemed to leap up into his mouth. His eye had caught the
momentary gleam of something moving in the thick foliage that bordered
the road at the bottom of the hill. He recognized it in an instant--the
silver mounting of a pistol. He turned and shouted to Jack.

"Crack! crack!" and Fred felt the wind of a bullet as it sung past.
"Crack! crack!" but that was wider of the mark. The Happy Thought under
full speed had bounded down the hill, and the danger-point was passed.
He could hear faint shouts behind him and the short quick tramp of
horses' hoofs. Was it possible that they had escaped?

With fingers tightly clutched on the handle-bars Fred kept the Happy
Thought in the middle of the road. The road-bed was smooth and hard, but
the front wheel was acting oddly. There was something that looked like a
white patch on the tire, and, yes, there could be no doubt about it, it
was leaking badly. Evidently the tire had been cut by a bullet, and in a
few seconds more the air would be out of it. Just ahead was a curve
which for the moment would put them out of sight; they must stop in time
to take to the woods. In his excitement Fred put his hand behind him and
shut off the oil. The Happy Thought stopped just around the curve, and
Fred jumped off and looked around.

_Jack and the express bag had disappeared._

In his bewilderment and