rank found it easy to discover where Henri was confined. He
was to be tried by court-martial early in the morning, and for the night
he was in a room on the ground floor of the Hotel de Ville.

"He's only a boy," said a Bavarian corporal. "No need to guard him
closely. Even if he escaped, where could he go? Our men are everywhere."

Frank smiled to himself. He had made a discovery a day or two before
that had not escaped his mind. That afternoon he managed to make
certain preparations unobserved. And when night came he was ready to
hazard his own liberty, and his life, if that should prove to be
necessary, in an attempt to rescue Henri. He knew the room in which
Henri was confined. It was on the side of the Hotel de Ville that
overlooked the river. No sentries were posted there, and it was easy for
Frank to get to a spot directly underneath Henri's window. The other
bank of the river was well guarded, and that was why no sentries watched
the side on which was the town hall. It was argued, Frank supposed, that
anyone escaping must attempt to swim the river and that when they tried
to climb the other bank it would be easy to find them.

In principle, too, that was a good idea. What it did not take into
account was the discovery that Frank had made--and kept to himself.

It was just before midnight when he began a faint tapping at Henri's
window. He used a light bamboo cane, tipped with soft cloth, so that the
sound, audible to anyone in the room, would not carry more than a few
feet. And he tapped out his signal in the Morse code very slowly,
knowing that Henri would hear and understand.

In a few moments there was the sound of the window opening very gently.
And then Henri slipped down beside him, taking the short drop by hanging
from the window with his hands. He seized Frank's hand.

"I knew you would try to help me," he whispered. "But I had better go
back. We cannot escape. There are sentries on the other bank of the
Somme. They would catch us together, and you would be a prisoner, too."

"Follow me," said Frank. "Take off your shoes. Drop quietly into the
water--make no sound of a splash. Swim after me. I shall show you
something you do not expect to see."

Frank slipped into the water. Both boys were expert swimmers, and Frank,
leading the way, slipped along in the deep shadow, without a sound.
Henri swam after him. At last Frank stopped and whispered to Henri.

"You see this buttress? Dive just beyond it,