Night after night passed, one night of work by each man followed by two of such rest as lying spoon fashion upon a hard floor allowed. On the seventeenth night of the new tunnel work, Colonel Rose was digging away in it. It was over fifty feet long. His candle flickered and went out. The foul air closed in upon him. Hats were fanning to and fro, back in Rat Hell, fifty feet away, but the fresh air did not reach him. He felt himself suffocating. With one last effort he thrust his strong fists upward and broke through the surface. Soon revived by the rush of fresh air into the tunnel, he dragged himself out and found himself in the yard that had been their aim. The tunnel had reached its goal. He climbed out and studied the situation. A high fence screened the yard from Libby. A shed with an easily opened door screened it from the street. At three A.M., February 6, 1864, Colonel Rose returned to prison. That morning he told his news. Most of the men wanted to try for freedom the next night, but there was much to do to erase all traces of their work, so that, if the tunnel were not forthwith discovered after their flight, it could be used later by other fugitives. With a rare unselfishness, they waited for sixty hours. Meanwhile each of the fifteen had been authorized to tell one other man, so that thirty in all could make their escape together. Colonel Rose felt that this was the limit. A general prison-delivery would, he believed, result in a general recapture. Such a secret, however, was too mighty to keep a whisper of it spread through the prison. When Hans Rolf had saved Tom's life, he had been at once taken into the inner councils of the tunnel group. He had not expressed as much joy in the plan as Tom had expected. The reason of this was now revealed. He declined to go. "You see," he explained to Colonel Rose and Tom, "I gave my parole not to try to escape when Tom here was sick. I had to do so in order to be allowed to take care of him. I made up my mind not to ask to be relieved from it because if I had the Confeds. might have suspected some plan to escape was on hand. And they seem to have forgotten all about it, for they haven't cancelled it. So you see I'm bound in honor not to go. Don't bother, Tom." The boy's face showed the agony he felt that Hans Rolf's kindness to him should now bar Hans Rolf's way to freedom. "Don't bother. 'Twon't be long before I'll be exchanged. And p'raps I can save some lives here by staying. Don't bother. It's all right. I rather like this boarding-house." The giant's great laugh rang out. The heartiness of it amazed the weary men scattered about the room. It brought smiles to lips that had not smiled for many a day. Laughter that comes from a clean heart does good to all who hear it. It was clear that Rolf could not go. He was an officer and a gentleman. Honor forbade it. Sadly, Tom left him.