“Y-yes,” said Bill, wrinkling his forehead.  “Of course, the trouble with water is that one bit of it looks pretty much like the next bit.  I don’t know if that had occurred to you.

“It had,” smiled Antony.  “Let’s come and have a look at it.”

They walked to the edge of the copse, and lay down there in silence, looking at the pond beneath them.

“See anything?” said Antony at last.

“What?”

“The fence on the other side.”

“What about it?”

“Well, it’s rather useful, that’s all.”

“Said Sherlock Holmes enigmatically,” added Bill.  “A moment later, his friend Watson had hurled him into the pond.”

Antony laughed.

“I love being Sherlocky,” he said.  “It’s very unfair of you not to play up to me.”

“Why is that fence useful, my dear Holmes?” said Bill obediently.

“Because you can take a bearing on it.  You see—­”

“Yes, you needn’t stop to explain to me what a bearing is.”

“I wasn’t going to.  But you’re lying here,” he looked up “underneath this pine-tree.  Cayley comes out in the old boat and drops his parcel in.  You take a line from here on to the boat, and mark it off on the fence there.  Say it’s the fifth post from the end.  Well, then I take a line from my tree we’ll find one for me directly and it comes on to the twentieth post, say.  And where the two lines meet, there shall the eagles be gathered together.  Q.E.D.  And there, I almost forgot to remark, will the taller eagle, Beverley by name, do his famous diving act.  As performed nightly at the Hippodrome.”

Bill looked at him uneasily.

“I say, really?  It’s beastly dirty water, you know.”

“I’m afraid so, Bill.  So it is written in the book of Jasher.”

“Of course I knew that one of us would have to, but I hoped, well, it’s a warm night.”

“Just the night for a bathe,” agreed Antony, getting up.  “Well now, let’s have a look for my tree.”

They walked down to the margin of the pond and then looked back.  Bill’s tree stood up and took the evening, tall and unmistakable, fifty feet nearer to heaven than its neighbours.  But it had its fellow at the other end of the copse, not quite so tall, perhaps, but equally conspicuous.

“That’s where I shall be,” said Antony, pointing to it.  “Now, for the Lord’s sake, count your posts accurately.”

“Thanks very much, but I shall do it for my own sake,” said Bill with feeling.  “I don’t want to spend the whole night diving.”

“Fix on the post in a straight line with you and the splash, and then count backwards to the beginning of the fence.”

“Right, old boy.  Leave it to me.  I can do this on my head.”

“Well, that’s how you will have to do the last part of it,” said Antony with a smile.

He looked at his watch.  It was nearly time to change for dinner.  They started to walk back to the house together.