e to pull over."

"Would you know the tall man again?"

The driver shook his head.

"I don't know as I should, sir. You see, it was raining, and he had his
collar up round his neck and his hat pulled down over his eyes, so as I
couldn't right see his face."

"Describe him as best you can."

"He was a tall man, longer than what you are, and broad too. A big man,
I should call him."

"How was he dressed?"

"He had a waterproof, khaki color--about the color of your own--with the
collar up round his neck."

"His hat?"

"His hat was a soft felt, dark, either brown or green, I couldn't
rightly say, with the brim turned down in front."

"And his face? Man alive, you must have seen his face when he gave you
the shilling."

The driver stared helplessly. Then he answered:

"I couldn't be sure about his face, not with the way he had his collar
up and his hat pulled down. It was raining and blowing something crool."

"Did the other man reply when the tall one spoke into the cab?"

"Didn't hear no reply at all, sir."

Inspector Willis thought for a moment and then started on another tack.

"Did you hear a shot?" he asked sharply.

"I heard it, sir, right enough, but I didn't think it was a shot at
the time, and I didn't think it was in my cab. It was just when we were
passing the Apollo Theater, and there was a big block of cars setting
people down, and I thought it was a burst tire. 'There's somebody's tire
gone to glory,' I sez to myself, but I give it no more thought, for it
takes you to be awake to drive up Shaftesbury Avenue when the theaters
are starting."

"You said you didn't think the shot was in your cab; why do you think so
now?"

"It was the only sound like a shot, sir, and if the man has been shot,
it would have been then."

Willis nodded shortly. There was something puzzling here. If the shot
had been fired by the other occupant of the cab, as the man's evidence
seemed to indicate, there would certainly have been powder blackening on
the coat. If not, and if the bullet had entered from without, the other
passenger would surely have stopped the car and called a policeman.
Presently he saw that some corroborative evidence might exist. If the
bullet came from without the left-hand window must have been down, as
there was no hole in the glass. In this case the wind, which was blowing
from the north-west, would infallibly have driven in the rain, and drops
would still show on the cushions. He must