Nibet manifested an intelligence of which his outer appearance gave no indication; but it seems to be an established fact that the inventive faculties, even of men of inferior mental quality, are sharpened when they are engaged in mischief.
"For the last three weeks," he said, "about a score of masons have been working in the prison, repairing the roof and doing up some of the cells. Cell number 129, the one next yours, is empty, and there are no bars on the window; the masons go through that cell and that window to get on to the roof. They knock off work soon after six o'clock. The gate-keeper knows them all, but he does not always look closely at their faces when they go by, and you might perhaps be able to go out with them.
"In the bundle that I gave you there is a pair of workman's trousers, and a waistcoat and a felt hat; put those on. At about a quarter to six, the men who went up on to the roof through the cell, come down by way of the skylights to the staircase that leads to the clerk's office, pass the office, where they are asked no questions, cross the two yards and go out by the main gate. I will open the door of your cell a few minutes before six, and you must go into the empty cell next yours, slip up on to the roof and take care to hide behind the chimney stacks until the men have done work. Let them go down in front of you, and follow behind with a pick or a shovel on your shoulder, and when you are passing the clerk, or anywhere where you might be observed, mind you let the men go a yard or two in front of you. When the gate is just being shut after the last workman, call out quietly, but as naturally as you can, 'Hold on, M. Morin; mind you don't lock me in; I'm not one of your lodgers; let me out after my mates.' Make some joke of that sort, and when you are once outside the gate, by George, my boy, you'll have to vamoose!"
Gurn listened attentively to the warder's instructions. Lady Beltham must, indeed, have been generous and have made the man perfectly easy on the score of his own future.
"In one of the pockets of the clothes," Nibet went on, "I have put ten hundred-franc notes; you asked for more, but I could not raise it: we can settle that some other time."
Gurn made no comment.
"When will my escape be discovered?" he asked.
"I am on night duty," the warder answered. "Arrange your clothes on your bed to make it look as if you were in bed, and then they will think I might have been deceived. I go off duty at five; the next round is at eight. My mate will open the door of the cage, and by that time you will be miles away."
Gurn nodded comprehension. Time did not permit of longer conversation. The bell had rung some minutes ago, proclaiming that the exercise time was over. The two men hurried upstairs to cell number 127 on the third floor, and the prisoner was locked in alone, while Nibet went about his duty as usual.