A month went by in which I learned nothing new. Then I came into theoffice one day and found a stranger waiting for me. A tall, well-dressedMexican. He sat by the open window smoking a brown cigarette that smelledstrong. He was wearing his black hair longer than we do north of the border. Hewas also wearing green sunglasses. He stood up politely.'Senor Marlowe?''What can I do for you?'