Suddenly I turned to Cuthbert Vane.

“How do you know, really, that he ever did leave the island?” I demanded.

“Who—­the copra chap?  Well, why else was the cabin cleared out so carefully—­no clothes left about or anything?”

“That’s true,” I acknowledged.  The last occupant of the hut had evidently made a very deliberate and orderly business of packing up to go.

We drifted about the cove for a while, then steered into the dim murmuring shadow of the treasure-cavern.  It was filled with dark-green, lisping water, and a continual resonant whispering in which you seemed to catch half-framed words, and the low ripple of laughter.  Mr. Vane indicated the point at which they had arrived in their exploration among the fissures opening from the ledge.

The place held me with its fascination, but we dared not linger long, for as the tide turned one man would have much ado to manage the boat.  So we slid through the archway into the bright sunshine of the cove, and headed for the camp.

As we neared the beach we saw a figure pacing it.  I knew that free stride.  It was Dugald Shaw.  And quite unexpectedly my heart began to beat with staccato quickness.  Dugald Shaw, who didn’t like me and never looked at me—­except just sometimes, when he was perfectly sure I didn’t know it.  Dugald Shaw, the silent, unboastful man who had striven and starved and frozen on the dreadful southern ice-fields, who had shared the Viking deeds of the heroes—­whom just to think of warmed my heart with a safe, cuddled, little-girl feeling that I had never known since I was a child on my father’s knee.  There he was, waiting for us, and splashing into the foam to help Cuthbert beach the boat—­he for whom a thousand years ago the skalds would have made a saga—­

The b. y. hailed him cheerfully as we sprang out upon the sand.  But the Scotchman was unsmiling.

“Make haste after your tools, lad,” he ordered.  “We’ll have fine work now to get inside the cave before the turn.”

Those were his words; his tone and his grim look meant, So in spite of all my care you are being beguiled by a minx—­

It was his tone that I answered.

“Oh, don’t scold Mr. Vane!” I implored.  “Every paradise has its serpent, and as there are no others here I suppose I am it.  Of course all lady serpents who know their business have red hair.  Don’t blame Mr. Vane for what was naturally all my fault.”

Not a line of his face changed.  Indeed, before my most vicious stabs it never did change.  Though of course it would have been much more civil of him, and far less maddening, to show himself a little bit annoyed.

“To be sure it seems unreasonable to blame the lad,” he agreed soberly, “but then he happens to be under my authority.”

“Meaning, I suppose, that you would much prefer to blame me,” I choked.

“There’s logic, no doubt, in striking at the root of the trouble,” he admitted, with an air of calm detachment.