Almost immediately a faint star-like light shone out at a distance on their left, and the lantern was hidden and the star disappeared.
“Why’s that?” whispered Mark.
“Let the other boat know the slaver’s dropping down,” was whispered back.
“But is she?” said Mark, excitedly.
“No doubt about that, my lad. Pull steady.”
The men obeyed, and the boat was steered in a zigzag fashion down the river, but there was no sign of the slaver. If she was dropping down it was so silently that her presence was not detected, and at last a fresher feeling in the air warned the occupants of the first cutter that they must be nearing the mouth of the river.
“Light,” whispered Mark, pointing off to his right, where, faintly seen, there was a feeble ray.
“Signal,” whispered the lieutenant. The lantern was shown, and there was an answering light from behind them, proving that the one forward must be at sea.
“It’s a recall,” said the lieutenant, with a sigh of relief; “give way, my lads.” Then to Mark: “The captain must be uneasy about us, or he would never show that light. It’s like letting the slaver know. Bah! what an idiot I am. That’s not our light. Pull, my lads, pull! That must have been shown by the ship we are after.”
As he spoke the light disappeared, and a fresh one appeared from astern.