"You see, Watson," he explained in the early hours of the morning

as we sat over a glass of whisky and soda in Baker Street, "it

was perfectly obvious from the first that the only possible

object of this rather fantastic business of the advertisement of

the League, and the copying of the Encyclopaedia, must be to get

this not over-bright pawnbroker out of the way for a number of

hours every day. It was a curious way of managing it, but,

really, it would be difficult to suggest a better. The method was

no doubt suggested to Clay's ingenious mind by the color of his

accomplice's hair. The 4 pounds a week was a lure which must draw

him, and what was it to them, who were playing for thousands?

They put in the advertisement, one rogue has the temporary

office, the other rogue incites the man to apply for it. and

together they manage to secure his absence every morning in the

week. From the time that I heard of the assistant having come for

half wages, it was obvious to me that he had some strong motive

for securing the situation."

"But how could you guess what the motive was?"

"Had there been women in the house, I should have suspected a

mere vulgar intrigue. That, however, was out of the question. The

man's business was a small one, and there was nothing in his

house which could account for such elaborate preparations, and

such an expenditure as they were at. It must, then, be something

out of the house. What could it be? I thought of the assistant's

fondness for photography, and his trick of vanishing into the

cellar. The cellar! There was the end of this tangled clew. Then

I made inquiries as to this mysterious assistant and found that I

had to deal with one of the coolest and most daring criminals in

London. He was doing something in the cellar--something which

took many hours a day for months on end. What could it be, once

more? I could think of nothing save that he was running a tunnel

to some other building.

"So far I had got when we went to visit the scene of action. I

surprised you by beating upon the pavement with my stick. I was

ascertaining whether the cellar stretched out in front or behind.

It was not in front. Then I rang the bell, and, as I hoped, the

assistant answered it. We have had some skirmishes, but we had

never set eyes upon each other before. I hardly looked at his

face. His knees were what I wished to see. You must yourself have

remarked how worn, wrinkled, and stained they were. They spoke of

those hours of burrowing. The only remaining point was what they

were burrowing for. I walked round the corner, saw the City and

Suburban Bank abutted on our friend's premises, and felt that I

had solved my problem. When you drove home after the concert I

called upon Scotland Yard and upon the chairman of the bank

directors, with the result that you have seen."

"And how could you tell that they would make their attempt

to-night?" I asked.

"Well, when they closed their League offices that was a sign that

they cared no longer about Mr. Jabez Wilson's presence--in other

words, that they had completed their tunnel. But it was essential

that they should use it soon, as it might be discovered, or the

bullion might be removed. Saturday would suit them better than

any other day, as it would give them two days for their escape.

For all these reasons I expected them to come to-night."

"You reasoned it out beautifully," I exclaimed in unfeigned

admiration "It is so long a chain, and yet every link rings

true."

"It saved me from ennui," he answered, yawning. "Alas! I already

feel it closing in upon me. My life is spent in one long effort

to escape from the commonplaces of existence. These little

problems help me to do so."

"And you are a benefactor of the race," said I.

He shrugged his shoulders. "Well, perhaps, after all, it is of

some little use," he remarked. " 'L'homme c'est rien--l'oeuvre

c'est tout,' as Gustave Flaubert wrote to George Sand."