e to come. In the pocket of the injured
man was a receipt for a diamond-studded gun-metal cigar-case, purchased
the day of the outrage. And Walen, the jeweller, proved beyond a doubt
that the case I claimed was purchased at his shop."

Bell nodded gravely.

"Which places you in an exceedingly awkward position," he said.

"A mild way of putting it," David replied. "If that fellow dies the
police have enough evidence to hang me. And what is my defence? The story
of my visit to No. 219. And who would believe that cock-and-bull story?
Fancy a drama like that being played out in the house of such a pillar of
respectability as Gilead Gates."

"It isn't his house," said Bell. "He only takes it furnished."

"In anybody else your remark would be puerile," David said, irritably.

"It's a deeper remark than you are aware of at present," Bell replied. "I
quite see your position. Nobody would believe you, of course. But why not
go to the post-office and ask the number of the telephone that called you
up from London?"

The question seemed to amuse David slightly. Then his lips were drawn
humorously.

"When my logical formula came back I thought of that," he said. "On
inquiring as to who it was rang me up on that fateful occasion I learnt
that the number was 0017 Kensington and that--"

"Gates's own number at Prince's Gate," Bell exclaimed. "The plot
thickens."

"It does, indeed," David said, grimly. "It is Wilkie Collins gone mad,
Gaboriau _in extremis_, Du Boisgobey suffering from _delirium tremens_.
I go to Gates's house here, and am solemnly told in the midst of
surroundings that I can swear to that I have never been there before;
the whole mad expedition is launched by the turning of the handle of a
telephone in the house of a distinguished, trusted, if prosaic,
citizen. Somebody gets hold of the synopsis of a story of mine, Heaven
knows how--"

"That is fairly easy. The synopsis was short, I suppose?"

"Only a few lines, say 1,000 words, a sheet of paper. My writing is very
small. It was tucked into a half-penny open envelope--a magazine office
envelope, marked 'Proof, urgent.' There were the proofs of a short story
in the buff envelope."

"Which reached its destination in due course?"

"So I hear this morning. But how on earth--"

"Easily enough. The whole thing gets slipped into a larger open envelope,
the kind of big-mouthed affair that enterprising firms send out circulars
and patterns with. This falls int