the mighty stone table on the cleared slope, which by its construction gave evidence of a knowledge of mechanics of which the present-day Polynesian is entirely ignorant.  I recalled the Nan-Tauch ruins and the tombs of the mysterious Chan-te-leur kings Ola-Sipa and Ola-Sopa in the Carolines, the tolmas and the langis of the Marshall and Gilbert groups, and I wished the Professor anything but pleasant dreams.  The place seemed waiting for the return of its dead.  The scenery possessed that singular expectancy that compels one to turn around every few moments to convince one’s self that an unfriendly watcher is not immediately in the rear.

Still keeping in the shadows, we circled the camp till we were in front of the stone table, but just when I took a step into the moonlight space before it, Holman grasped my arm and drew me back.

“Look!” he gurgled.  “Look! there he is again!”

All doubts concerning the youngster’s previous observations were swept away at that moment.  A head and shoulders rose suddenly above the black line of the immense flat stone, remained there for the space of three minutes, then dropped back so that we could not see it from the position in which we stood.

“Take the two front pillars!” whispered Holman.  “I’ll watch the two back ones.  Come on!”

We dashed across the open space, the youngster rushing to the rear, while I ran to the front columns.  It was impossible for any one to descend unless we saw him, and with nerves on a tension we walked around the huge supports and watched anxiously for the midnight watcher to descend.

We must have remained on guard for twenty minutes or more, but there was no sign of the spy.  Around us the massive structure cast a patch of velvety shadow, but not the slightest sound came from above.

Holman tired of the inactivity, and stepped across to where I was standing.  “I’m going to climb that chestnut tree and see if the beggar is still there,” he murmured.  “You stop here till I take an observation.”

He darted across to the big Pacific chestnut and climbed hurriedly, while I walked round and round the square pillars and strained my ears for the slightest sound that would give a hint that the person on the roof of the mysterious table was preparing to descend.

A low whistle from Holman pierced the silence, and I answered.

“Come up here,” he cried softly.  “He’s given us the slip.”

I climbed the tree to the branch where the young fellow sat awaiting me.  From his position he had a clear view of the top of the big table, and as I reached him I looked through an opening in the thick leaves.  The top of the stone was empty!

“Do you think he slipped down while I was climbing the tree?” asked Holman.

“I’m certain he didn’t,” I answered.  “It would have been impossible.”