While Melton and the colonel were carrying on this conversation, Guy rose and went down to the water, with the intention of gathering some food, for he, too, was hungry.
The canoe was pulled partly on shore, and as it leaked a little the water had all collected in the stern, where Sir Arthur still lay in merciful sleep, thus wetting the rugs.
Guy noticed this, and with a view to making the sleeper more comfortable, he slid the canoe down until it lay flat in the water. It still retained a slight hold of an inch or two on the sand.
A sudden cry from the Greek brought him back in a hurry to the top of the island.
His companions were staring out on the lake, and Canaris was pointing with a trembling hand at some unseen object.
“What is the matter?” cried Guy. “What do you see?”
“Hush,” said the colonel, holding up a warning finger. “Something is moving out on the lake. Do you hear it splashing in the water?”
As yet nothing could be seen, but the noise was very plain and distinct, a steady swish! swish! not unlike the beating of a little steamer.
A chilling fear grew on them as they listened to this strange, mysterious sound.
“Whatever it is, it is moving in a circle round the island,” said Guy, “and keeping an equal distance from the shore.”