"You say that as if it was something remarkable!" said Frank, with a laugh. "Of course they're cheerful. They've got faith in their leaders, and they know, I suppose, that a retreat is often necessary. They'll turn the tables before long." "It seems strange to be where it is so quiet," said Frank, when they had finally passed beyond sound of the skirmishing on the extreme left of the allied line, formed by the French force through which they had passed. "I'm expecting to see Germans every time we make a turn." "So am I," said Henri. "And why shouldn't we? If they are trying to turn the allied flank, we're as likely to see them in this direction as not." "Look here," said Frank, "you're perfectly right. We haven't got orders to make particularly good time. Let's keep on right to Abbeville. That's at the mouth of the Somme. Then we can turn toward Boulogne. If there are Germans around here at all they'll be in that direction. We might get some trace of their cavalry. Or we might do what we did before, strike some of their infantry. I don't think we're so likely to do that, though." "We'll try it, anyhow," said Henri. And so they turned toward St. Pol, instead of making the sharp turn at right angles that would have brought them to Amiens. Here there were traces, indeed, of a German invasion. Peasants, alarmed by the reports of Uhlans seen at Arras and near Boulogne, were in full flight. "We needn't bother about that," said Frank. "Anything that these people know the intelligence department has found out. No troops advancing at all openly could get by the aeroplanes without being seen. And I think the railroad in this direction has been watched. I saw a lot of aeroplanes flying over this way this afternoon, and there would be more from Boulogne. There are English warships there, I've heard, and their naval flyers would cover this part of the 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."