Having transformed himself by disguise.
Arriving at dawn he began to walk up and down the streets and watch the early stirring of the inhabitants. So, before long, he drew up at the door of Baba Mustapha, who, though old, was already seated at work upon his cobbler's bench. The robber accosted him. "I wonder," said he, "to see a man of your age at work so early. Does not so dull a light strain your eyes?" "Not so much as you might think," answered Baba Mustapha. "Why, it was but the other day that at this same hour I saw well enough to stitch up a dead body in a place where it was certainly no lighter." "Stitch up a dead body!" cried the robber, in pretended amazement, concealing his joy at this sudden intelligence. "Surely you mean in its winding sheet, for how else can a dead body be stitched?" "No, no," said Mustapha; "what I say I mean; but as it is a secret, I can tell you no more." The robber drew out a piece of gold. "Come," said he, "tell me nothing you do not care to; only show me the house where lay the body that you stitched." Baba Mustapha eyed the gold longingly. "Would that I could," he replied; "but alas! I went to it blindfold." "Well," said the robber, "I have heard that a blind man remembers his road; perhaps, though seeing you might lose it, blindfold you might find it again." Tempted by the offer of a second piece of gold, Baba Mustapha was soon persuaded to make the attempt. "It was here that I started," said he, showing the spot, "and I turned as you see me now." The robber then put a bandage over his eyes, and walked beside him through the streets, partly guiding and partly being led, till of his own accord Baba Mustapha stopped. "It was here," said he. "The door by which I went in should now lie to the right." And he had in fact come exactly opposite to the house which had once been Cassim's, where Ali Baba now dwelt.
The robber, having marked the door with a piece of chalk which he had provided for the purpose, removed the bandage from Mustapha's eyes, and leaving him to his own devices returned with all possible speed to the cave where his comrades were awaiting him.
Soon after the robber and cobbler had parted, Morgiana happened to go out upon an errand, and as she returned she noticed the mark upon the door. "This," she thought, "is not as it should be; either some trick is intended, or there is evil brewing for my masters house." Taking a piece of chalk she put a similar mark upon the five or six doors lying to right and left; and having done this she went home with her mind satisfied, saying nothing.
In the meantime the robbers had learned from their companion the success of his venture. Greatly elated at the thought of the vengeance so soon to be theirs, they formed a plan for entering the city in a manner that should arouse no suspicion among the inhabitants. Passing in by twos and threes, and by different routes, they came together to the market-place at an appointed time, while the captain and the robber who had acted as spy made their way alone to the street in which the marked door was to be found. Presently, just as they had expected, they perceived a door with the mark on it. "That is it!" said the robber; but as they continued walking so as to avoid suspicion, they came upon another and another, till, before they were done, they had passed six in succession. So alike were the marks that the spy, though he swore he had made but one, could not tell which it was. Seeing that the design had failed, the captain returned to the market-place, and having passed the word for his troop to go back in the same way as they had come, he himself set the example of retreat.
When they were all reassembled in the forest, the captain explained how the matter had fallen, and the spy, acquiescing in his own condemnation, kneeled down and received the stroke of the executioner.