He did not wait long, for a strange cry--a confused sound of barking and howling--broke over the Pampas, followed next instant by the report of the carbine, which made the uproar a hundred times worse.

Glenarvan and Robert woke in alarm, and started to their feet instantly.

"What is it?" exclaimed Robert.

"Is it the Indians?" asked Glenarvan.

"No," replied Thalcave, "the AGUARAS."

"AGUARAS?" said Robert, looking inquiringly at Glenarvan.

"Yes," replied Glenarvan, "the red wolves of the Pampas."

They seized their weapons at once, and stationed themselves beside the Patagonian, who pointed toward the plain from whence the yelling resounded.

Robert drew back involuntarily.

"You are not afraid of wolves, my boy?" said Glenarvan.

"No, my Lord," said the lad in a firm tone, "and moreover, beside you I am afraid of nothing."

"So much the better. These AGUARAS are not very formidable either; and if it were not for their number I should not give them a thought."

"Never mind; we are all well armed; let them come."