exclaimed Delaney clutching the detective's shoulder and
wheeling him around. "Say, stand right there a minute. Right in that
light. What's that on your chin? Right under the tip of your left ear.
Turn around a little more!"

Drew raised his left hand and rubbed it across his face. He pinched the
lobe of his ear between his thumb and index finger. He whistled with
frosty amazement as he eyed his nail and thumb.

"What to blazes!" he said. "What's that?"

"Turn around! Right under this arc light. Say, Chief, how did you get
that spot of black on your neck? You've smeared it all over your
collar."

"I don't know. What's it look like?"

"Soot!"

"Soot?"

"Sure, Chief. Lampblack or soot!"

Drew arched his dark brows as he rubbed his finger-tips together. He
held them up to the stronger light. He turned and glanced back through
the silent walls of the street down which they had walked. He took one
step toward the east.

"Hold on!" said Delaney. "Where are you going?"

"Going back!"

"Why, Chief!"

"Smell that stuff! Smell it!" Drew thrust his fingers under Delaney's
wrinkled nose. "Smell it, good and strong!" he snapped bitterly. "What
is it?"

"By God, Chief, it's powder, I smell! Gunpowder, it is!"

"Umph! I must have gotten it from that gat!"

"You couldn't, Chief. That gun was polished up like a whistle. Besides,
how would the spot come to be under your left ear?"

Drew furrowed his brow. He swung in the snow with new decision. "Come
on!" he said. "We'll think this over! I didn't see any soot on that
gat. I don't know where I got it either. Could it have been there for
some time?"

"Sure, Chief. I just happened to notice it. Light's bright." Delaney
nodded toward the arc.

"Did you get a good look at my face in Stockbridge's?"

"Can't say that I did, Chief. I was too busy with that howler thing and
that magpie and that murder, to see anything. You might of got it there
without me noticing it. It wasn't there in the taxicab. I'll swear to
that."

Drew passed his fingers across his nostrils like a man sampling
perfume. He repeated the motion. He scraped some of the powder from his
nails with a pocket knife and dropped the sample into the crease of an
envelope which he carefully folded and crammed into his pocket.

"I'll have that analyzed," he said, as they turned toward Fifth Avenue.
"Another trifle in a chain of circumstance. Think it over, Delaney. It
resembles and smells like powder which