It was more difficult to get back than it had been to wriggle out. With a great effort he worked his way along the recess, and had just reached the floor of the room when his foot kicked the chisel, and it sped with a clatter across the floor. Immediately afterwards he heard a step in the passage. His jailer must have detected the noise, and would certainly come to discover its cause. It would be impossible to strip off jacket and waistcoat and wriggle out before the man entered, discovered his flight, and gave the alarm or perhaps cut the rope. With a sinking of the heart Bob listened. Was he to fail at the last moment? Perhaps the man would not come in after all. But no; the steps halt at the door; there is a light in the crack below. Bob hears the man fumbling for his keys; a key is inserted in the padlock; the bolt is drawn. By this time Bob, with lightning decision, is behind the door. It opens heavily on its rusty hinges, and half the room is lit up by the dim lantern carried by a Siberian infantryman, who peers into the room, and seeing nothing to his left, advances a few paces to light up the other half. At this moment Bob springs at him like a tiger. One crushing blow beneath the jaw, and the Russian falls backward like a log, his lantern clattering to the floor and being instantly extinguished. Two seconds passed, seconds crowded with the most rapid thinking hard-pressed prisoner ever accomplished. The noise would draw the man’s comrades from below. They must be kept out at all costs. But even if they were excluded, the soldier might be only stunned, or perhaps dazed, and would recover in time to cut the rope. There was nothing at hand with which to tie him up, no time to cut a piece off the rope and retie it to the crowbar. He might kill the man, but the thought was banished the same instant that it occurred to him. Two seconds; then, even as he heard the shouts of men and the trampling of heavy footsteps far below, Bob stooped, lifted the ponderous figure, and, with a strength of which he would not have believed himself capable, hurled him out into the corridor across the head of the staircase. [Illustration: Bob surprises his Jailer]