sequence； what would you think？〃
〃That someone had changed the tape in that one recorder at a later time。〃
〃Yes。 And that's exactly what happened。〃
〃One tape was switched later？〃
〃Yes。〃
I frowned。 〃But why？ All of the tapes were replaced at nine o'clock。 So none of the replacements showed the murder； anyway。〃
〃Correct；〃 Connor said。
〃Then why switch one tape after that？〃
〃Good question。 It's puzzling。 I couldn't make sense of it for a long time。 But now I know；〃 Connor said。 〃You have to remember the timing。 The tapes were all changed at nine。 Then one tape was changed again at ten…fifteen。 The obvious assumption was that something important happened between nine o'clock and ten…fifteen； that it was recorded on the tape； and the tape was therefore taken away for some reason。 I asked myself： what could this important event be？〃
I thought back。 I frowned。 I couldn't think of anything。
Theresa began to smile and nod； as if something had just amused her。 I said； 〃You know？〃
〃I can guess；〃 she said； smiling。
〃Well；〃 I said。 〃I'm glad everyone seems to know the answer except me。 Because I can't think of anything important being recorded on that tape。 By nine o'clock； the yellow barrier was up； isolating the crime scene。 The girl's body was on the other side of the room。 There were a lot of Japanese standing by the elevators； and Graham was calling me on the phone for help。 But nobody actually began an investigation until I got there at about ten。 Then we had a lot of back and forth with Ishiguro。 I don't think anybody crossed the tape until almost ten…thirty。 Say ten…fifteen at the earliest。 So if somebody looked at a recording； all it would show is a deserted room； and a girl lying on the table。 That's all。〃
Connor said； 〃Very good。 Except you have forgotten something。〃
Theresa said； 〃Did anybody cross the room？ Anybody at all？〃
〃No；〃 I said。 〃We had the yellow barrier up。 Nobody was allowed on the other side of the tape。 In fact… 〃
And then I remembered。 〃Wait a minute！ There was somebody！ That little guy with the camera；〃 I said。 〃He was on the other side of the barrier； taking pictures。〃
〃That's right；〃 Connor said。
〃What little guy？〃 she said。
〃A Japanese guy。 He was taking pictures。 We asked Ishiguro about him。 He said his name was； ah 。 。 。〃
〃Mr。 Tanaka；〃 Connor said。
〃That's right； Mr。 Tanaka。 And you asked Ishiguro for the film from his camera。〃 I frowned。 〃But we never got it。〃
〃No；〃 Connor said。 〃And frankly； I never thought we would。〃
Theresa said； 〃This man was taking pictures？〃
〃I doubt that he was actually taking pictures；〃 Connor said。 〃Perhaps he was； because he was using one of those little Canons… 〃
〃The ones that shoot video stills； instead of film？〃
〃Right。 Would there be any use for those； in retouching？〃
〃There might be；〃 she said。 〃The images might be used for texture mapping。 They'd go in fast； because they were already digitized。〃
Connor nodded。 〃Then perhaps he was taking pictures； after all。 But it was clear to me that his picture…taking was just an excuse to allow him to walk on the other side of the yellow line。〃
〃Ah；〃 Theresa said； nodding。
I said； 〃How do you know that？〃
〃Think back；〃 Connor said。
I had been standing facing Ishiguro when Graham yelled： Aw； Christ； what is this？ And I looked back over my shoulder and saw a short Japanese man about ten meters beyond the yellow tape。 The man's back was turned to me。 He was taking pictures of the crime scene。 The camera was very small。 It fitted into the palm of his hand。
〃Do you remember how he moved？〃 Connor said。 〃He moved in a distinctive way。〃
I tried to recall it。 I couldn't。
Graham had gone forward to the tape； saying： For Christ's sake； you can't be in there。 This is a goddamned crime scene。 You can't take pictures！ And there was a general uproar。 Graham was yelling at Tanaka； but he continued to be entirely focused on his work； shooting the camera and backing toward us。 Despite all the yelling； Tanaka didn't do what a normal person would do … turn around and walk toward the tape。 Instead； he backed up to the yellow stripe and； still turned away； ducked his head and went under it。
I said； 〃He never turned around。 He backed up all the way。〃
〃Correct。 That is the first mystery。 Why would he back up？ Now； I think； we know。〃
〃We do？〃
Theresa said； 〃He was repeating the walk of the girl and the killer in reverse； so it would be laid down on videotape and he would have a good record of where the shadows in the room were。〃
〃That's right；〃 Connor said。
I remembered that when I protested； Ishiguro had said to me： This is our employee。 He works for Nakamoto Security。
And I had said： This is outrageous。 He can't take pictures。
And Ishiguro had explained： But this is for our corporate use。
And meanwhile the man had disappeared in the crowd； slipping through the knot of men at the elevator。
But this is for our corporate use。
〃Damn it！〃 I said。 〃So Tanaka left us； went downstairs； and removed a single tape； because that tape had a record of his own walk across the room； and the shadows he cast？〃
〃Correct。〃
〃And he needed that tape to make changes in the original tapes？〃
〃Correct。〃
I was finally beginning to understand。 〃But now； even if we can figure out how the tapes were altered； they won't stand up in a court of law； is that right？〃
〃That's right；〃 Theresa said。 〃Any good lawyer will make sure they're inadmissible。〃
〃So the only way to go forward is to get a witness who can testify to what was done。 Sakamura might know； but he's dead。 So we're stuck unless we can somehow get our hands on Mr。 Tanaka。 I think we better get him in custody right away。〃
〃I doubt that will ever happen；〃 Connor said。
〃Why not？ You think they'll keep him from us？〃
〃No； I don't think they have to。 It is very likely that Mr。 Tanaka is already dead。〃
Connor immediately turned to Theresa。 〃Are you good at your job？〃
〃Yes；〃 she said。
〃Very good？〃
〃I think so。〃
〃We have little time left。 Work with Peter。 See what you can extract from the tape。 Gambatte： try very hard。 Trust me that your efforts will be rewarded。 In the meantime； I have some calls to make。〃
I said； 〃You're leaving？〃
〃Yes。 I'll need the car。〃
I gave him the keys。 〃Where are you going？〃
〃I'm not your wife。〃
〃I'm just asking；〃 I said。
〃Don't worry about it。 I need to see some people。〃 He turned to go。
〃But why do you say Tanaka is dead？〃
〃Well； perhaps he's not。 We'll discuss it when there is more time。 Right now； we have a lot to finish before four o'clock。 That is our true deadline。 I think you have surprises in store for you； kōhai。 Just call it my chokkan； my intuition。 Okay？ You have trouble； or something unexpected； call me on the car phone。 Good luck。 Now work with this lovely lady。 Urayamashii ne！ 〃
And he left。 We heard the rear door close。
I said to Theresa； 〃What did he say？〃
〃He said he envies you。〃 She smiled in the darkness。 〃Let's begin。〃
She pressed buttons on the equipment in rapid succession。 The tape rolled back to the beginning of the sequence。
I said； 〃How are we going to do this？〃
〃There are three basic approaches to learn how video has been doctored。 The first is blur and color edges。 The second is shadow lines。 We can try to work with those elements； but I've been doing that for the last two hours； and I haven't gotten very far。〃
〃And the third method？〃
〃Reflected elements。 I haven't looked at them yet。〃
I shook my head。
〃Basically； reflected elements … REs … are portions of the scene that are reflected within the image itself。 Like when Sakamura walks out of the room； and his face is reflected in the mirror。 There are almost certainly other reflections in that room。 A desk lamp may be chrome； and it may show the people； distorted； as they pass。 The walls of the conference room are glass。 We may be able to pull a reflection off the glass。 A silver paperweight on a desk； with a reflection in it。 A glass vase of flowers。 A plastic container。 Anything shiny enough to make a reflection。〃
I watched her reset the tapes； and prepare to run forward。 Her one good hand moved