He was safe enough for the moment. But obviously he couldn't risk leaving the building the way he had entered. The guard might be going on his rounds--or the closing of the door might be a ruse. Frowning, Hendley tried to sort out in his memory the various functions of this utility tunnel. If he remembered correctly, it led to a large water pump station, and there were branches along the way feeding into smaller underground facilities. It should be no trick to find another way out. He could hear the water pump when he was still a good distance away from the station. It would probably be routinely guarded. He chose at random one of the branching tunnels. A few minutes later he stepped into the heating room of what he guessed was an arcade. The heating and air-conditioning unit was of a size and type designed to serve a series of small shops and offices. No one saw him when he emerged from the room into a walkway behind a row of shops. He strode casually along the walk and stepped out into a crowded street. Orienting himself, Hendley found that he was only a quarter of a mile from the museum. He began hurrying through the noisy evening crowd. Theater and sports arena marquees were winking. Throngs filled the busy arcades, the sidewalk venders, the discussion halls, the public gyms. A news announcer's voice blared from a street corner viewscreen. Still talking about the Merger. Hendley saw the steps of the museum ahead. He didn't know exactly how long his roundabout escape had taken. He had given Ann a five-minute start. Add about fifteen minutes to that, he guessed. She would be anxious now, worrying. A few people were entering the museum. A guard stood by the entry, watching the crowd on the street below with apparently casual interest. A young woman emerged from the museum. She wore a yellow coverall and her hair was dark. Baffled, Hendley walked slowly past the museum steps. ABC-331 was not there. * * * * * The guard at the Historical Museum's entry was watching him now. Hendley merged with the flow of pedestrians, allowing himself to be carried along. He had been wandering back and forth in front of the building for twenty minutes. Long enough to draw attention to himself. Longer than necessary to know that Ann was gone. He couldn't understand her actions. The chilling fear kept recurring that somehow she had been detected leaving the tunnel. But reason argued that in that event the museum guards would have made a careful search for her male companion. Then why had she vanished? Looking back, trying to recall everything that had happened between them, every word that had been spoken, Hendley recognized evasiveness in some of her replies, duplicity in some of her actions. She had been trying to avoid him when she left the Research Center early that day. Moreover, she had suggested that they leave separately. She had planned to disappear.