I was getting
to business.

'What is he--international socialist, or anarchist, or what?' I asked.

'Pure-blooded Boche agent, but the biggest-sized brand in the
catalogue--bigger than Steinmeier or old Bismarck's Staubier. Thank God
I've got him located ... I must put you wise about some things.'

He lay back in his rubbed leather armchair and yarned for twenty
minutes. He told me how at the beginning of the war Scotland Yard had
had a pretty complete register of enemy spies, and without making any
fuss had just tidied them away. After that, the covey having been
broken up, it was a question of picking off stray birds. That had taken
some doing. There had been all kinds of inflammatory stuff around, Red
Masons and international anarchists, and, worst of all, international
finance-touts, but they had mostly been ordinary cranks and rogues, the
tools of the Boche agents rather than agents themselves. However, by
the middle of 1915 most of the stragglers had been gathered in. But
there remained loose ends, and towards the close of last year somebody
was very busy combining these ends into a net. Funny cases cropped up
of the leakage of vital information. They began to be bad about October
1916, when the Hun submarines started on a special racket. The enemy
suddenly appeared possessed of a knowledge which we thought to be
shared only by half a dozen officers. Blenkiron said he was not
surprised at the leakage, for there's always a lot of people who hear
things they oughtn't to. What surprised him was that it got so quickly
to the enemy.

Then after last February, when the Hun submarines went in for
frightfulness on a big scale, the thing grew desperate. Leakages
occurred every week, and the business was managed by people who knew
their way about, for they avoided all the traps set for them, and when
bogus news was released on purpose, they never sent it. A convoy which
had been kept a deadly secret would be attacked at the one place where
it was helpless. A carefully prepared defensive plan would be
checkmated before it could be tried. Blenkiron said that there was no
evidence that a single brain was behind it all, for there was no
similarity in the cases, but he had a strong impression all the time
that it was the work of one man. We managed to close some of the
bolt-holes, but we couldn't put our hands near the big ones. 'By this
time,' said he, 'I reckoned I was about ready to change my methods. I
had been working