“The moving picture is bright but not comprehensive,” he said, returning to a former analogy.  “In fact I’m beginning to see already that, no matter what we get at the end of the reel, there are still a few preliminary scenes that should come in at the beginning.”

“I’ve begun at the beginning, Mr. Ganns.”

But Peter shook his head.

“Half the battle is to know the beginning of a case.  I’ll almost go so far as to say that, given the real beginning, the end should be assured.  You’ve not begun at the beginning of the Redmayne tangle, Mark.  If you had, the clue to this labyrinth might be in your hands to-day.  The more I hear and the more I think, the more firmly am I convinced that the truth we are out to find can only be discovered by a deal of hard digging in past times.  There is a lot of spade work demanded and you, or I, may have to return to England to do it—­unless we can get the information without the labour.  But I’ve no reason to count on any luck of that sort.”

“I should like to know the nature of the ground I failed to cover,” said Brendon; but Peter was not disposed to enlighten him at present.

“Needn’t bother yet,” he said.  “Now talk about yourself and give the case a rest.”

They chatted until the dawn, by which time their train had reached Paris, and an hour or two later they were on their way to Italy.

Mr. Ganns had determined to cross the Lakes and arrive unexpectedly at Menaggio.  He had now turned his mind once more to the problem before him and spoke but little.  He sat with his notebook open and made an occasional entry as he pursued his thoughts.  Mark read newspapers and presently handed a page to Mr. Ganns.

“What you said about acrostics interested me,” he began.  “Here’s one and I’ve been trying to guess it for an hour.  No doubt it ought to be easy; but I expect there’s a catch.  Wonder if it will puzzle you.”

Peter smiled and dropped his notebook.

“Acrostics are a habit of mind,” he said.  “You grow to think acrostically and be up to all the tricks of the trade.  You soon get wise to the way that people think who make them; and then you’ll find they all think alike and all try to hoodwink you along the same lines.  If you tempt me on to acrostics, you’ll soon wish you had not.”

Mark pointed to the puzzle.

“Try that,” he said.  “I can’t make head or tail of it; yet I dare say you’ll thrash it out if you’ve got the acrostic mind.”

Mr. Ganns cast his eye over the puzzle.  It ran thus: 

When to the North you go,
The folk shall greet you so.
. . . . . . . . .

1.  Upright and light and Source of Light
2.  And Source of Light, reversed, are plain.
3.  A term of scorn comes into sight

      And Source of Light, reversed again.

The American regarded the problem for a minute in silence, then smiled and handed the paper back to Brendon.