JILL TRIED TO TELL HERSELF that Ben had gone charging off on another Scent and simply had forgotten (or had not taken time) to let her know.  But she did not believe it.  Ben, incredibly busy as he was, owed much of his success, both professional and social, to meticulous attention to human details.  He remembered birthdays and would rather have welched on a poker debt than have forgotten to write a bread-and-butter note.  No matter where he had gone, nor how urgent the errand, he could have - and would have! - at least taken two minutes while in the air to record a reassuring message to her at her home or at the Center.  It was an unvarying characteristic of Ben, she reminded herself, the thing that made him a lovable beast in spite of his many faults.