The day she discovered the third letter, she had of course expected nothing unusual. It was a typical midsummer day in Boston-hot, humid, with the same news that usually accompanied such weather-a few assaults brought on by aggravated tensions and two early afternoon murders by people who had taken it too far. Theresa was in the newsroom, researching a topic on autistic children. The Boston Times had an excellent database of articles published in previous years from a variety of magazines. Through her computer she could also access the library at Harvard University or Boston University, and the addition of literally hundreds of thousands of articles they had at their disposal made any search much easier and less time-consuming than it had been even a few years ago. In a couple of hours she had been able to find almost thirty articles written in the last three years that had been published in journals she had never heard of, and six of the titles looked interesting enough to possibly use. Since she would be passing by Harvard on the way home, she decided to pick them up then. As she was about to turn off her computer, a thought suddenly crossed her mind and she stopped. Why not? she asked herself. It's a long shot, but what can I lose? She sat down at her desk, accessed the database at Harvard agai