"I don't play billiards." "Neither do I," said Kent, "but I can find out.

Quick! The nearest book-store.

I must buy a book on billiards." With a wave of the arm, Kent vanished.
The Inspector stood for a moment in thought.
"Gone!" he murmured to himself (it was his habit to murmur all really important speeches aloud to himself).

"Now, why did Throgton telephone to me to put a watch on Kent?
Ten dollars a day to shadow him! Why ?".