Chapter 21 Strange Sounds.—A Night Attack.—Kennedy and Joe in the Tree.—Two Shots.—"Help! help!"—Reply in French.—The Morning.—The Missionary. —The Plan of Rescue. The night came on very dark. The doctor had not been able to reconnoitre the country. He had made fast to a very tall tree, from which he could distinguish only a confused mass through the gloom. As usual, he took the nine-o'clock watch, and at midnight Dick relieved him. "Keep a sharp lookout, Dick!" was the doctor's good-night injunction. "Is there any thing new on the carpet?" "No; but I thought that I heard vague sounds below us,