o cross over and walk past our offices. A taxi was
coming up the road, so I waited for a moment on the pavement until
it had passed. The back part of the vehicle was open, and as it came
opposite to me, the light from one of the big electric standards fell
clear on the face of the man inside. He was sitting bolt upright,
looking straight out ahead, but in spite of his opera hat and his
evening dress I recognized him at once. It was the man with the
scar--the man I had imagined to be tracking me on the previous
evening.

CHAPTER XII

A SCRIBBLED WARNING

I have never been slow to act in moments of sudden emergency, and in
rather less than a second I had made up my mind. The mere idea
of stalking one's own shadower was a distinctly attractive one;
surrounded as I was by a baffling sense of mystery and danger I jumped
at the chance with an almost reckless enthusiasm.

Coming up behind was another taxi--an empty one, the driver leaning
back in his seat puffing lazily at a pipe. I stepped out into the road
and signalled to him to pull up.

"Follow that taxi in front," I said quickly. "If you keep it in sight
till it stops I'll give you five shillings for yourself."

All the languor disappeared from the driver's face. Hastily knocking
out his pipe, he stuffed it into his pocket, and the next moment we
were bowling up Victoria Street hard on the track of our quarry.

I sat back in the seat, filled with a pleasant exhilaration. Of course
it was just possible that I was making a fool of myself--that the
gentleman in front was as innocent of having spied on my movements as
the Bishop of London. Still if that were the case there could be no
harm in following him, while if he were really one of McMurtrie's
friends a closer acquaintance with his methods of spending the evening
seemed eminently desirable.

Half way along Whitehall my driver quickened his pace until we were
only a few yards behind the other taxi. I was just going to caution
him not to get too near, when I realized that unless we hung on as
close as possible we should probably lose it in the traffic at the
corner of the Strand. The soundness of this reasoning was apparent a
moment later, when we only just succeeded in following it across the
Square before a policeman's hand peremptorily barred the way.

Past the Garrick Theatre, across Long Acre, and up Charing Cross Road
the chase continued with unabated vigour. At the Palace the other
driver turne