"In a business suit of speckled brown. Derby hat. He wore a black mustache and had a diamond in his shirt-front. That's all the description the negro could give."
"Did you make any other discoveries?"
"Yes, one more, and an important one, Nick. There's a man on L Street, near the river, who knows something. The negro saw him talking with the dark-faced fellow some fifteen minutes before the note-changing proposition was broached. The negro has just returned from a day's absence from town, and that's why his story has not yet reached the ears of the Washington sleuths."
"What is the name of the man who lives on L Street?"
"Prosper Craven. He is a man of family: used to keep the grocery and has some money, though he is far from rich."
"What is his reputation? Did you learn?"
"His reputation is good. But he is a silent, reserved man and does not mingle much among his neighbors."
"I must see him at once. Meanwhile, wire Chief Wittman at San Francisco, asking him if he knows anything of one Arthur Mannion, giving description."
"What's your idea?"
"I'll tell you later. It is in the hatching process. It may be a chicken, it may be a duck."