She shrugged.
'What about the headaches?'
'I still get them.' Suspicion shadowed her eyes. 'Sometimes the Midrin helps. Sometimes it just makes me throw up. The only thing that really works is Fiorinal. But I don't have any of that.'
'You don't need any of that.'
'You're not the one who gets the headaches.'
'I get plenty of headaches. You don't need to be on barbiturates,' I answered. 'You're sleeping and eating all right, and getting exercise?'
'What is this, a doctor's appointment?'
'In a matter of speaking, since it just so happens I'm a doctor. Only you didn't make an appointment but I'm nice enough to see you anyway.'
A smile tugged at the corner of her mouth. 'I'm doing fine,' she said less defensively.
'Something happened today,' I said again.
'I guess you haven't talked to Commander Penn.'
'Not since this morning. I didn't know you knew her.'
'Her department's on-line with us, with CAIN. At twelve noon CAIN called the Transit Police VICAP terminal. I guess you had already left for the airport.'
I nodded, my stomach tightening as I thought of Davila's beeper going off in the morgue. 'What was the message this time?' I asked.
'I have it if you want to see it.'
'Yes,' I said.
Lucy went into her room and returned carrying a briefcase. She unzipped it and pulled out a stack of papers, handing me one that was a printout from the VICAP terminal located in the Communications Unit, which was under Frances Penn's command. It read:
— — -MESSAGE PQ21 96701 001145 BEGINS- — —
FROM:-CAIN
TO: — ALL UNITS amp; COMMANDS
SUBJECT: — DEAD COPS
TO ALL COMMANDS CONCERNED:
MEMBERS WILL, FOR THE PURPOSE OF SAFETY WHEN RESPONDING TO OR BEING ON PATROL IN THE SUBWAY TUNNELS, WEAR HELMETS. — — -MESSAGE PQ21 96701 001145 ENDS- — —
I stared at the printout for a while, unnerved and inflamed. Then I asked, 'Is there a username associated with whoever logged on to type this?'
'No.'
'And there's absolutely no way to trace this?'
'Not by conventional means.'
'What do you think?'
'I think when ERF was broken into, whoever got into CAIN planted a program.'
'Like a virus?' I asked.
'It is a virus, and it has been attached to a file that we just haven't thought of. It's allowing someone to move inside our system without leaving tracks.'
I thought of Gault backlit by his flashlight in the tunnel last night, of endless rails leading deeper into darkness and disease. Gault moved freely through spaces most people could not see. He nimbly stepped over greasy steel, needles and the fetid nests of humans and rats. He was a virus. He had somehow gotten into our bodies and our buildings and our technology.
'CAIN is infected by a virus,' I said. 'In summary.'
'An unusual one. This isn't a virus oriented toward crashing the hard disk or trashing data. This virus isn't generic.
It is specific for the Crime Artificial Intelligence Network because its purpose is to allow someone access to CAIN and the VICAP database.
This virus is like a master key. It opens up every room in the house.'
'And it's attached to an existing program.'
'You might say it has a host,' she said. 'Yes. Some program routinely used. A virus can't cause its damage unless the computer goes through a routine or subroutine which causes a host program — like autoexec.bat in DOS — to be read.'
'I see. And this virus is not embedded in any files that are read when the computer is booted, for example.'
Lucy shook her head.
'How many program files are there in CAIN?'
'Oh my God,' she said. 'Thousands. And some of them are long enough to wrap around this building. The virus could be attached anywhere, and the situation is further complicated because I didn't do all of the programming. I'm not as familiar with files others wrote.'
Others meant Carrie Grethen, who had been Lucy's programming partner and intimate friend. Carrie had also known Gault and was responsible for the ERF break-in. Lucy would not talk about her and avoided saying her name.
'Is there any possibility this virus might be attached only to programs Carrie wrote?' I asked.
The expression did not change on Lucy's face. 'It might be attached to one of the programs I didn't write. It might also be attached to one I did. I don't know. I'm looking. It may take a long time.'
The telephone rang.
'That's probably Jan.' She got up and went into the kitchen.
I glanced at my watch. I was due down in the unit in half an hour. Lucy placed her hand over the receiver. 'Do you care if Jan drops by? We're going running.'
'I don't mind in the least,' I said.
'She wants to know if you want to run with us.'
I smiled and shook my head. I couldn't keep up with Lucy even if she smoked two packs a day, and Janet could pass for a professional athlete. The two of them gave me the vague sensation of being old and left in the wrong drawer.