As soon as the panel was replaced they mounted the stairs.  Before beginning they had seen that there were no lights in any of the windows, and feeling sure that the house was deserted they groped their way upstairs without hesitation until they reached the attics in the sloping roof.  They entered one of these facing the street, opened the casement, in which oiled paper took the place of glass, and stepped down on to the parapet.  Their course was now easy.  The divisions between the houses were marked by walls some six feet high extending from the edge of the parapet over the roof.  They were able to climb these, however, without having to use their cord, one helping the other up and then being assisted by him.  They had left the cooking pan and their tools, with the exception of the crowbar, behind them, and had fastened their wooden shoes round their necks.  The sun during the day had melted the snow that had fallen in the morning, but light flakes were again beginning to come down fast.

“I don’t care how hard it snows as long as it keeps on,” Hector said in a low voice in answer to an exclamation from Paolo when the first flake fell upon his face.  “The harder the better, for in that case no sentry could see us half a dozen paces away.  There is another advantage.  The wind is from the north, and we have only to keep the driving snow on our right cheeks to make our way straight to the fortress, whereas with an overcast sky on such a dark night as this we should very soon lose all idea of the direction that we were going in.”

Being obliged to use great caution to avoid noise while getting over the walls, it took them half an hour to reach the end of the street.  They had, while waiting before commencing their operations, twisted one of their sashes, and then wound it round the hook so thickly that this would fall almost noiselessly upon the ground.  The snow prevented them from seeing six feet below them, but they felt sure that there must be a narrow lane between the house and the wall.  They had during the day bought a length, equal to that of their rope, of strong string.

“I have got it as you ordered it, master,” Paolo said as they came out of the shop, “but it would never bear our weight.”

“I think it might do in case of necessity,” Hector said.  “In fact, I am sure it would.  It does not require a great thickness of new cord to hold a man’s weight; but I don’t want it for that.”

Paolo walked silently along for some time, and then said:  “If it is not wanted to carry our weight, master, I cannot think what it is wanted for.”

“It is wanted to get the hook down with.  You see when we get down into the street there would be little chance of getting the hook off its hold.  We shall most likely want it again, and certainly we shall want the rope.  I have been puzzling over it, and I think I have found a way at last.  My idea is to fasten this thin rope to the point of the hook, then, on pulling upon it the point will rise until it gets level with the top of the wall on which it is fixed, and we can then shake it down without difficulty.  I don’t know whether it will act, but I think that it ought to do so; an upward pull at the point must, I should think, lift it as far as the edge.”