e a Major-General at the least.

"They will do their best to follow up my idea at the Front, and I
shall start a campaign here. For I become more and more convinced that
the head centre of the German secret service is here in London. Paris,
even before the war, was too watchful, and now is as hot as Hell.
London reeked with spies, and though we locked up the worst of them
when war broke out, lots still remain. If you only knew how many we
laid by the heels and keep shut up without any trial, or nonsense of
that sort, you would be surprised. It is only since the Defence of the
Realm Act was passed that England has become a free country. We keep a
drag-net going continually, we have hundreds of agents in all
suspected quarters, but this wilderness of bricks and mortar is too
big even for us. Once an enemy agent has got himself into an English
or Allied uniform, he is horribly difficult to run down. That is where
you, and those like you, come in. Are you sure, my dear madame, that
you can pass without detection as a Frenchwoman or a French-Belgian?"

Madame Gilbert put up her left hand, and began to tick off her
qualifications. "My father was a Swede, my mother was Irish, I was
educated in France from the age of three to eighteen, I married an
Italian. Brussels I know almost as well as dear Paris. I can be
Parisienne or Bruxelloise--whichever you wish, Mr. Dawson."

"Good," said Dawson. "What I want of you is this. Whenever here in
London you see a French or Belgian officer wearing the badges of the
Flying Corps, mark him down. Make his acquaintance somehow; you will
know how. Entertain him, fascinate him, let him entertain you; fool
him as you would fool me if I let you; worm out his secrets, if he has
any. If you get upon a promising track, go strong; let the man make
love to you--he will, whoever he is, if you give him half a
chance--intoxicate him with those confounded eyes of yours. If you can
find only one who is in the enemy's service, you will be fully repaid
for all your trouble."

"It is a largish contract," murmured Madame thoughtfully.

"There are not so very many flying officers," said Dawson, "and they
are all young. You will work through them pretty quickly. Most of them
will be the genuine article upon whom you need not waste much time.
But the others, those whom I suspect, you must grab hold of and never
let go, whatever happens."

"I hope," said Madame primly, "that you do not expect me to do
anyth