then there was a collar
or collars on the bullet, which we didn't find. The same thing was
discovered by examination of the shells which the Germans fired at
Paris. There was no rifling on those long-range projectiles. The bands
dropped off after the shell left the gun."

"Then this bullet was fired at long range?" Fosdick was openly
incredulous.

"No! Again we have the impossibility or seeming impossibility. I
examined that library, both before and after the murder. No shot could
have been fired from the outside so that a bullet would reach the old
man. If that were the case there would have been an opening in the
walls or at the windows or the ventilators. Besides, we have the powder
burns on the millionaire's head. We are squarely confronted with a
paradox. Riddle me that paradox and we will go a long ways toward
finding the man who murdered Stockbridge."

Fosdick frowned. "I can't see it at all," he confessed. "I still hold
to the theory that we should third degree all of the servants. I've got
some of them. If they don't squeal, I'll get the others!"

Drew glanced at his watch. "Personally," he said, "I'm of the opinion
that you will not get anything out of them. I think it was a mistake to
arrest them. It would have been far better to trail the butler and the
doorman and see if they connected with anybody."

"I'm doing this!" exclaimed Fosdick with asperity. "I've got charge of
this case, Drew. I got charge and I don't want any meddling. I've my
own methods."

"All right," said the detective. "All right! I want a check-up on the
finger prints and then I'll be going. I had to come to you for this.
You have such an interesting collection."

"Here's your answer!" said the commissioner, rising and striding around
the desk. "Take this bullet and look it over. Put it in your pocket.
And----"

Drew turned swiftly. The messenger stood in the doorway. He came
forward as Fosdick nodded. He passed over the hastily developed prints
which Drew had taken. The commissioner glanced at them, frowned, held
them to the light, then said:

"We'll try these on the Man Who Can't Be Beat! He's the best in the
world. He'll know in three minutes who made these prints if the fellow
is on our records."

The fingerprint expert nodded to Drew as they entered a huge room which
was lined with mahogany cabinets in the manner of a filing system in a
mail-order house. Fosdick passed the five photos into this man's hand.
He smiled as t