The men received their orders in silence, but a suppressed sigh told of their eagerness and readiness to act.

A minute later there was a sharp rattling sound, a savage growl, and a loud burst of laughter.

The first cutter had come in contact with the second, and directly after there was a whirring, brushing sound of branches sweeping over the boats, one of which bumped against a root and nearly capsized.

“Tut, tut, tut!” ejaculated the lieutenant; “back water, my lads! We are doing no good here. It is impossible to see where we are going.”

There was a slight splashing, and the boats began to descend the stream, swept along by the tide for a time, till they lay on their oars again.

“What’s that, Mr Russell?” whispered Mark, all at once.

“What? I heard nothing but one of the oars badly muffled.”

“I didn’t near anything. I meant what’s that I can smell?”

The lieutenant started, and just then there was a peculiarly offensive, sickening odour perceptible.

“No mistaking that,” whispered the lieutenant; and, giving orders, a lantern was taken from beneath the sail, and shown above the gunwale of the boat.