Father Lucien made a sign of agreement.  “I will come to see her to-morrow,” he said, but Thirlwell knew that Agatha would never learn from him that Strange’s canoe had not been accidentally capsized.

Early next morning Thirlwell went to the tail-pool, but nothing except some driftwood washed about in the eddy.  The latter had worn out a deep hollow and he scrambled over the rocks in order to look down into its revolving depths.  There was nothing there, and when going back he made his way across some worn slabs that had been covered until the water sank to an unusually low level.  By and by he stopped at the edge of a pool.  A small round object that was not the color of the stones lay at the bottom.

Thirlwell knelt down and rolling up his sleeve got the object out.  It was made of white metal that had tarnished but not corroded, and looked like an old-fashioned pocket tobacco-box.  The thing was well made, for he could hardly find the joint of the lid and below the latter there was some engraving.  He rubbed it with a little fine sand and then started as he read a name.  It was Strange’s tobacco-box and a light dawned on him.

He knew now why Driscoll had haunted the reefs when the water was low, and thought he knew what was inside the box.  This was the thing Strange had taken with him.  But Driscoll had looked in the wrong place.  The box was heavy, but perhaps a flood had rolled it down the rapid, or it had fallen from Strange’s pocket when the stream washed his rotting clothes away.

Thirlwell shook the box and something rattled inside, after which he noted a dark smear round the edge of the lid.  He scraped this with his knife and thought the stuff was a waterproof gum the freighters used to caulk their canoes.  It looked as if Strange had carefully made the joint watertight, and Thirlwell’s curiosity was strongly excited, but the box was not his.  It was too early to look for Agatha, and he waited with some impatience until she came out of the shack and sat down in the sunshine after breakfast.

“I think this was your father’s,” he said, putting the box in her hand, and told her how he had found it.

Agatha started.  “Yes; I gave it him on his birthday long since.  It was bright then; old English pewter, I think.  I saw it in a little store where they sold curiosities, and had it engraved.”

Somewhat to Thirlwell’s annoyance, Scott came up with Father Lucien, whom he presented to Agatha, but she did not put the box away.

“Mr. Thirlwell found this in the river, but the lid is fast,” she said.  “Will somebody help me to open it?”

Scott took the box into the shack, where he had some tools, and brought it back with the lid just raised above its socket.  He gave it to Agatha and was going away when she stopped him.

“I would like you and Father Lucien to wait.  You knew my father, and I think there is something important in the box.”