country."

Suddenly Henri slowed down the car. He kept one hand on the wheel, the
car moving slowly forward, but his gaze was fixed on the sky. Finally he
stopped the car altogether.

"Look up there," he said, quietly, to Frank. "Do you see that light?
First I thought it was a star. But there aren't any other stars, and now
I'm sure it's moving. Do you see?"

He pointed, and Frank's eyes followed his finger.

"You're right," he said. "Hello! Now it's gone--no, there it is again!
See, it flashes and then disappears! It's some sort of a signal from the
air. Keep the car still."

He tried to follow the flashes of the light, hoping to read the message
if it was in Morse code. But he soon found that it was not. And then
Henri cried out sharply.

"If it's a signal, it's being answered from over there!" he said. "See,
there's a light waving there. It looks as if it might be from the roof
of a house. I--"

CHAPTER XVI

A DARING EXPLOIT

Frank leaped out.

"Turn the car around first," he said. Henri obeyed. "Now try your
starter. Cut out the motor and then see if she starts quickly."

Henri, mystified, obeyed.

"Why?" he asked.

"Because when we want to start, we may have to do it in an awful hurry,"
said Frank. He searched the road for a moment. "Run her back a few feet
to where that big tree is. It's darker there than anywhere else around
here. All right, that's far enough. We'll have to take the chance of
something coming along while we're gone and bumping into her but I don't
believe there's much risk of that. Now, come on! And quiet! We've got to
get up to that place without being seen."

Cautiously they approached the house. No lights showed in any of its
windows; the place looked deserted. Indeed, all around it were traces
of hasty flight. It was a wayside inn, of a type common always in
France, commoner than ever since the spread of the craze for automobiles
and motor touring. Suddenly Frank stopped.

"Wait a minute for me," he said. "I've got to go back to the car. I
ought to have thought of it before."

"What do you want?"

"Batteries. I saw a coil of wire in the car and I want that, too. And
there must be batteries. A car like this would carry everything needed
for small repairs, wouldn't it?"

"Yes. I think you'll find them under my seat."

Frank was back in less than five minutes.

"All right," he said. "I don't know whether we'll have time to do what I
want or not, and whether I'