His eyes were keen. Sara Lee had suddenly a strange feeling that he was watching the couple who talked over their coffee, and that, oddly enough, the couple were watching him. Yet he was apparently giving his undivided attention to her. "Have you walked any to-day?" he asked her unexpectedly. Sara Lee remembered the bus, and, with some bitterness, the two taxis. "I haven't had a chance to walk," she said. "But you should walk," he said. "I--will you walk with me? Just about the square, for air?" And in a lower tone: "It is not necessary that those two should know the plan, mademoiselle." "I'll get my coat and hat," Sara Lee said, and proceeded to do so in a brisk and businesslike fashion. When she came down Henri was emerging from the telephone booth. His face was impassive. And again when in time Sara Lee was to know Henri's face better than she had ever known Harvey's, she was to learn that the masklike look he sometimes wore meant danger--for somebody. They went out without further speech into the clear cold night. Henri, as if from custom, threw his head back and scanned the sky. Then they went on and crossed into the square. "The plan," Henri began abruptly, "is this: You will be provided to-morrow with a passport to Boulogne. You will, if you agree, take the midnight train for Folkestone. At the railway station here you will be searched. At Folkestone a board, sitting in an office on the quay, will examine your passport." "Does any one in Boulogne speak English?" Sara Lee inquired nervously. Somehow that babel of French at the Savoy had frightened her. Her little phrase book seemed pitifully inadequate for the great things in her mind. "That hardly matters," said Henri, smiling faintly. "Because I think you shall not go to Boulogne." "Not go!" She stopped dead, under the monument, and looked up at him. "The place for you to go, to start from, is Calais," Henri explained. He paused, to let pass two lovers, a man in khaki and a girl. "But Calais is difficult. It is under martial law--a closed city. From Boulogne to Calais would be perhaps impossible." Sara Lee was American and her methods were direct. "How can I get to Calais?" "Will you take the chance I spoke of?" "For goodness' sake," said Sara Lee in an exasperated tone, "how can I tell you until I know what it is?" Henri told her. He even, standing under a street lamp, drew a small sketch for her, to make it clear. Sara Lee stood close, watching him, and some of the lines were not as steady as they might have been. And in the midst of it he suddenly stopped. "Do you know what it means?" he demanded. "Yes, of course." "And you know what date this is?" "The eighteenth of February." But he saw, after all, that she did not entirely understand. "To-night, this eighteenth of February, the Germans commence a blockade of this coast. No vessels, if they can prevent them, will leave the harbors; or if they do, none shall reach the other side!"