If they should discover that aperture, the cavern might be attacked from the rear and the front at the same time, and then the captain feared his guns would not much avail.
Of course, during the darkness which would soon prevail there was no reason to expect a rear attack, and the captain satisfied himself with leaving Mok at his former post, with instructions to give the alarm if he heard the slightest sound, and put Maka, as before, in the outer passage.

As for himself, he took an early nap in the evening, because at the very first break of dawn it would be necessary for him to be on the alert.
He did not know how much he had depended upon the lake as a barrier of defence, but now that it had gone, he felt that the dangers which threatened them from the Rackbirds were doubled..