He saw by the moonlight that the little island on which the hut stood was in the midst of the swamp.
If any one left it, he was bound to see them.
But not a soul met his view.
No one could leave the hut, cross the swamp and reach the mainland so quick that he could not see them escaping in such a short space of time.
Yet he failed to see any one in the swamp.
That convinced him that no one left the oasis.
And nobody was on the solid island of earth.
He could not have failed to observe them if they were there.
"What the deuce does this mean?" he gasped in bewilderment.
Then he finally returned to his partner.