ing him by a stranger!"

I glanced in the direction he had indicated and saw a tall, slim,
rather good-looking girl sauntering idly in our direction. Her
attention had, for the moment, been diverted by an advertisement upon
the wall.

"Quick!" cried my friend. "Let us slip back here."

And next moment we had repassed the barrier, back into the
booking-office.

"If she sees me her suspicions will be aroused--if they are not
already aroused," said my companion. "The fact that she is here gives
rise to the question whether she is really so innocent as she
pretends. She may know of her lover's escapades, and suspects me of
having followed her out to her home."

"If she does suspect, then she is cleverer than you anticipated," I
remarked.

"Yes. But in any case we had better act independently. You return to
the platform, for she has never seen you. You will remain well
concealed and watch them meet, while I shall be at the exit to
identify him if you find that you cannot get near enough to him
without courting observation."

As he spoke the bell was clanging, and there came the roar of the
engine entering the big echoing station.

I slipped back instantly upon the platform and standing at a point
against the corner of the bookstand where I hoped to escape
unobserved, I turned my head away as the train came along. Then, when
it drew up, I held my breath anxiously as I turned around.

The girl in navy blue was not far from me searching along the train
until, of a sudden, she espied a man in a dark overcoat and dark-green
velour hat, who had just alighted, carrying in his hand a small
leather case. His countenance was ruddy, and he had a small black
moustache.

My heart fell. The man was a stranger to me! The countenance was not
that of the man whom I had surprised in my bedroom at Madrid. He bent
and greeted her affectionately, but next moment it was apparent that
she was explaining something which caused his countenance to grow
serious.

He put one or two swift questions to her. Then halting suddenly, he
glanced at his watch.

I strove to get sufficiently near to look well into his face, but I
feared recognition.

Would he pass out of the exit where the famous Spanish detective was
awaiting him? Rivero knew Despujol by photographs, and indeed had been
present when he had been convicted on the last occasion a few years
before.

Mademoiselle's friend hesitated for some moments, and then accosting a
porter