At this moment a happy thought came up to answer the question. It flashed simultaneously through the minds of both. Both remembered the cavity in the tree; and without a word to one another—both acting under the same impulse—they glided inside, and stood in shadow dark as the dungeon itself!

They had scarce time to compose themselves ere the party of intruders came up, and stopped right under the tree. To their chagrin they saw this. They had hoped that such early travellers might be bent upon some distant journey, and that once past the spot they would be themselves free to continue their affectionate leave-taking.

They soon perceived that this was not to be. The new comers had halted close up to the trunk, directly in front of the cavity, and although enveloped in deep shadow their figures were distinguishable from the deeper shadow that surrounded the two spectators. Either of these could have touched them by stretching forth a hand!

Neither had thoughts of doing this. On the contrary, they stood motionless as marble, both silently striving to keep back their breath.

Six figures there were—six men—several of them carrying implements, at first taken for guns, but which, on more prolonged scrutiny, proved to be spades and shovels. From the way they were manipulating these tools it was evident they intended making use of them, and on the spot!

The occupants of the tree-cave where puzzled by these preparations. For what were they going to dig?

The blood of both ran cold at the thought of its being a grave. And both had it. What else could they have thought? Six men, armed with excavating implements, at that unearthly time of the night!

And a secret grave, too, for the body of some one whom they had murdered! Else why their stealthy movements, and their talking in low tones, scarce louder than a whisper?

Who could they be? And what their purpose?

These were the questions that came before the minds of Pierre Robideau and Lena Rook, only in thought; they dared not interrogate one another even in whispers. They stood silent, watching the development of events.