On Tuesday evening, February 9, 1864, when the chosen thirty had crawled down the inverted "S" and the rope-ladder to Rat Hell, Col. H. C. Hobart, who knew the secret, but had gallantly offered to stay behind, so that he could replace the tell-tale bricks in the fireplace, replaced them. But before he could get upstairs, some hundreds of men had come down. The secret was a secret no longer. There was a fierce struggle to get to the fireplace, a struggle all the fiercer because it had to be made in grim silence, for there was a sentry but a few feet away, on the other side of the wall, in the hospital. The bricks were taken out again. In all, one hundred and nine Union officers got through the hole. Then, warned by approaching daylight, the less fortunate in the fight for freedom put back the bricks and crept stealthily upstairs, resolved to try their luck the next night, if the tunnel were not before that discovered. Tom had wormed his way through the inverted "S" among the first fifteen. On the rope ladder he lost his hold and fell in a heap upon the floor of Rat Hell. The huge rodents swarmed upon him, squealing and biting. He almost shrieked with the horror of it, but he sprang to his feet, threw off his tormentors, and ran across the room to the opening of the tunnel. His ragged clothes were still more ragged and his face and hands were bleeding from rat-bites, but he cared nothing for all this. Was he not on his way to freedom? On his way, yes; but the way was a long one. He might never reach the end. When he had pushed and pulled himself through the tunnel; when he had come out into the yard and gone through the shed; and when, at the moment the sentry in the canal street was at the further end of his beat, he had slipped out of the doorway and turned in the opposite direction,--when all this had happened, he was out of prison, to be sure, but he was in the heart of the enemy's country, with all the risks of recapture or of death still to be run.