"One of us walked in his sleep and did this thing," I said feebly,
"or--or it has been filed by the constant stream of sand particles blown
against it by the wind, perhaps."

"Ah," said the Swede, turning away, laughing a little, "you can explain
everything!"

"The same wind that caught the steering paddle and flung it so near the
bank that it fell in with the next lump that crumbled," I called out
after him, absolutely determined to find an explanation for everything
he showed me.

"I see," he shouted back, turning his head to look at me before
disappearing among the willow bushes.

Once alone with these perplexing evidences of personal agency, I think
my first thought took the form of "One of us must have done this thing,
and it certainly was not I." But my second thought decided how
impossible it was to suppose, under all the circumstances, that either
of us had done it. That my companion, the trusted friend of a dozen
similar expeditions, could have knowingly had a hand in it, was a
suggestion not to be entertained for a moment. Equally absurd seemed the
explanation that this imperturbable and densely practical nature had
suddenly become insane and was busied with insane purposes.

Yet the fact remained that what disturbed me most, and kept my fear
actively alive even in this blaze of sunshine and wild beauty, was the
clear certainty that some curious alteration had come about in his
_mind_--that he was nervous, timid, suspicious, aware of goings on he