sing the room, she drew the curtains. I crept out into the road
again and by the same roundabout route came back to the empty house.
Feeling my way in the darkness of the shrubbery, I found the motor
bicycle which I had hidden there and I wheeled it down to the further
gate of the drive and waited.

I could see the doctor's door, and I saw him returning along the road.
As he appeared, from somewhere---I could not determine from where--came
a strange and uncanny wailing sound, a sound that chilled me like an
evil omen.

Even as it died away, and before Dr. Stuart had reached his door I
knew what it portended--that horrible wail. Some one hidden I knew not
where, had warned Zara el-Khala that the doctor returned! But stay!
Perhaps that some one was the dark-skinned chauffeur!

How I congratulated myself upon the precautions which I had taken to
escape observation. Evidently the watcher had placed himself somewhere
where he could command a view of the front door and the road.

Five minutes later the girl came out, the old housekeeper accompanying
her to the door, the car emerged from the lane, Zara el-Khala
entered it and was driven away. I could see no one seated beside the
chauffeur. I started my "Indian" and leapt in pursuit.

As I had anticipated, the route was Eastward, and I found myself
traversing familiar ground. From the south-west to the east of London
whirled the big car of mystery--and I was ever close behind it.
Sometimes, in the crowded streets, I lost sight of my quarry for a
time, but always I caught up again, and at last I found myself whirling
along Commercial Road and not fifty yards behind the car.

Just by the canal bridge a drunken sailor lurched out in front of my
wheel, and only by twisting perilously right into a turning called, I
believe, Salmon Lane, did I avoid running him down.

_Sacre nom!_ how I cursed him! The lane was too narrow for me to turn
and I was compelled to dismount and to wheel my "Indian" back to the
highroad. The yellow car had vanished, of course, but I took it for
granted that it had followed the main road. At a dangerous speed,
pursued by execrations from the sailor and all his friends, I set off
east once more turning to the right down West India Dock Road.

Arriving at the dock, and seeing nothing ahead of me but desolation
and ships' masts, I knew that that inebriated pig had spoiled
everything! I could have sat down upon the dirty pavement and wept,
so mortified