Ned continued on foot among the Tlascalans. Cos offered him no kindness whatever, and his pride would not let him ask for it. But when he looked at his sore and bleeding feet he always thought of the patient burro that he had lost. They marched several more days, and the road dropped down into the lowlands, into the tierra caliente. The air grew thick and hot and Ned, already worn, felt an almost overpowering languor. The vegetation became that of the tropics. Then, passing through marshes and sand dunes, they reached Vera Cruz, the chief port of Mexico, a small, unhealthy city, forming a semicircle about a mile in length about the bay. Ned saw little of Vera Cruz, as they reached it at nightfall, but the approach through alternations of stagnant marsh and shifting sand affected him most unpleasantly. Offensive odors assailed him and he remembered that this was a stronghold of cholera and yellow fever. He ate rough food with the Tlascalans again, and then Cos sent for him. "You have reached your home," said the General. "You will occupy the largest and most expensive house in the place, and my men will take you there at once. Do you not thank me?" "I do not," replied Ned defiantly. Yet he knew that he had much to dread. "You are an ungrateful young dog of a Texan," said Cos, laughing maliciously, "but I will confer my hospitality upon you, nevertheless. You will go with these men and so I bid you farewell." Four barefooted soldiers took Ned down through the dirty and evil-smelling streets of the city. He wondered where they were going, but he would not ask. They came presently to the sea and Ned saw before him, about a half mile away, a somber and massive pile rising upon a rocky islet. He knew that it was the great and ancient Castle of San Juan de Ulua. In the night, with only the moon's rays falling upon its walls, it looked massive and forbidding beyond all description. That cold shiver again appeared at the roots of the boy's hair. He knew now the meaning of all this talk of Santa Anna and Cos about their hospitality. He was to be buried in the gloomiest fortress of the New World. It was a fate that might well make one so young shudder many times. But he said not a word in protest. He got silently into a boat with the soldiers, and they were rowed to the rocky islet on which stood the huge castle. Not much time was wasted on Ned. He was taken before the governor, his name and age were registered, and then two of the prison guards, one going before and the other behind, led him down a narrow and steep stairway. It reminded him of his descent into the pyramid, but here the air seemed damper. They went down many steps and came into a narrow corridor upon which a number of iron doors opened. The guards unlocked one of the doors, pushed Ned in, relocked the door on him, and went away.