"In my heart I believe the same," assented Frank.  "But the tantalizing thing is that we haven't a bit of legal proof.  Rabig had that cut on his hand to explain the escape of the prisoner.  He seemed to be sleeping in his bunk that night I got back from the woods.  So far he has an alibi for everything.  We can't prove that he let himself be captured.  We can't prove that the Germans let him escape.  As for the information he claims to have, our suspicions are based only on what we know of the man's character."