Madness in relation to crime fascinated Tab. In his younger and more confident days, he had written a monograph on the subject which, amidst much profitless speculation had contained one gem of reasoning--the demand for corroborative evidence of criminal insanity. “Not evidence of a number of acts showing that an accused person is insanely cruel or pursues some one, apparently mad, course; but proof that in other relations he is abnormal. It is corroboration of homicidal tendencies, that a man insists on wearing odd boots of a different colour, or that he is in the habit of walking in the street without his trousers.” By this standard Rex was sane. So thought Tab with one half of his brain; the other half was taking stock of his immediate hope of escape. He was handcuffed behind; around his legs was a strap that was beyond the reach of his teeth. Between the links of the handcuffs and the strap a cord had been fastened and pulled tight so that his knees were doubled up without hope of straightening, unless he could succeed in breaking the cord. If that were possible, there was the key within reach. He made an effort, pulling up his legs still further and then jerking out his feet violently. The pain of it nearly made him faint, tough as he was. It seemed as if both his shoulders were dislocated. He could feel the cord; it was stout--perhaps with finger and nail he could pick it into shreds, fibre by fibre, or cut it with his thumb nail. After the wall was up his time would be very short unless the vault contained some other ventilator which neither Carver nor he had discovered. And yet even if the cord was broken he must wait until Lander had completed his work. It would be fatal, handcuffed as he was, to break out whilst Rex was on hand. His only chance was to free himself of the trussing cord whilst the work outside was in progress, get the key and by some contortion, unlock the door and employ his great strength to push through the newly laid bricks. The time would be short, but the cord was unbreakable. He rolled over on one side and bracing his feet against the leg of the table and his head against the wall, succeeded in getting on to his knees. Bound as he was, his eyes were at the level of the table-top. Shelves, steel shelves--perhaps there was a rough edge somewhere. He hobbled along on his knees and saw a promising place. Again he rolled over, this time on his back, raising his feet until, by straining, he brought the cord against the shelf. And all the time came the ring of the trowel and the crooning song of Rex Lander. He knew at once that it was a hopeless proposition. The sharp edge was beneath the shelf, he could only reach the upper surface. Crossing his legs to get a better purchase, he felt the strap slip upward. By pushing at the strap he brought it to below his knees and he could have yelled his delight for now the cord was slack and he would, he thought, at least be able to stand.