Next I began scanning screen after screen of the Trauma Registry’s records of victims who had survived long enough to be admitted to a hospital. I expected the information to be a problem, and it was. Hospitals released patient data only after it had been as sterilized and depersonalized as operating rooms. For purposes of confidentiality, names. Social Security numbers, and other identifiers were stripped away. There was no common link as the person traveled through the paperwork labyrinth of rescue squads, emergency rooms, various police departments, and other agencies. The sorry end of the story was that data about a victim might reside in six different agency data bases and never be matched, especially if there had been any entry errors along the way. It was possible, therefore, for me to discover a case that aroused my interest without having much hope of figuring out who the patient was or if he or she had eventually died.

Making a note of Trauma Registry records that might prove interesting, I exited the file. Finally, I ran a list command to see what old data reports, memos, or notes in my directory I could remove to free up space on the hard disk. That was when I spotted a file I did not understand.

The name of it was tty07. It was only sixteen bytes in size and the date and time were December 16, this past Thursday, at 4:26 in the afternoon. The file’s contents was one alarming sentence: I can’t find it.

Reaching for the phone, I started to call Margaret at home and then stopped. The directory Chief and its files were secure. Though anyone could change to my directory, unless he logged in with my user name and password, he should not be able to list the files in Chief or read them. Margaret should be the only person besides me who knew my password. If she had gone into my directory, what was it she could not find and who was she saying this to? Margaret wouldn’t, I thought, staring intensely at that one brief sentence on the screen.

Yet I was unsure, and I thought of my niece. Perhaps Lucy knew UNDO. I glanced at my watch. It was past eight on a Saturday night and in a way I was going to be heartbroken if I found Lucy at home. She should be out on a date or with friends. She wasn’t.

“Hi, Aunt Kay.” She sounded surprised, reminding me that I had not called in a while.

“How’s my favorite niece?”

“I’m your only niece. I’m fine.”

“What are you doing at home on a Saturday night?” I asked.

“Finishing a term paper. What are you doing at home on a Saturday night?”

For an instant, I did not know what to say. My seventeen-year- old niece was more adept at putting me in my place than anyone I knew.

“I’m mulling over a computer problem,” I finally said.

“Then you’ve certainty called the right department,” said Lucy, who was not given to fits of modesty. “Hold on. Let me move these books and stuff out of the way so I can get to my keyboard.”