Shooting in the Dark

moment.’
    ‘All right. We’ve got light and sound. These are two phenomena with different qualities. Light travels in a straight line.’
    ‘And it’s fast,’ added Sam.
    ‘Yeah, fast. Sound, on the other hand, doesn’t necessarily travel in a straight line. It’s slower, and it can get blown off course.’
    ‘Yeah,’ said Sam.
    ‘But something else,’ said JD. ‘When the band are playing we get complaints from the neighbourhood. Y’know why?’
    ‘Crap band?’
    JD let a wry smile invade his face. ‘Because sound can travel through walls. It’s much stronger than light. It can even go round corners.’
    ‘It plays tricks, though,’ said Sam.
    ‘Yeah, and so does light. Magicians and illusionists use it all the time.’
    ‘The other thing about sound,’ said Sam. ‘It gets reflected off the surfaces of things.’
    ‘Echoes. And how many times d’you mistake somebody’s voice? But the interesting thing is, you never get magicians and illusionists who work with sound. They always give us optical illusions because they are the kind that unsettle us. We believe in what we see much more than in what we hear. The things we see, or think we see, affect our sense of how things fit together in space.’
    ‘That’s right,’ said Sam. ‘We see things, but we don’t hear them. I remember when that woman was jumping up and down in the road, after I pushed her out of the ambulance. I didn’t hear a woman or a cop, I only heard the ranting.’
    ‘That’s right,’ said JD. ‘Sound gives us qualities. We never actually see light; we only see the things that are illuminated by it. But we actually hear pure sound, not something that is in the sound, but the thing itself.’
    ‘I suppose this all goes back to your man Descartes?’ said Sam.
    ‘Him and all the others who came before him, and the rest who followed him as well. It’s a philosophical perennial.’
    ‘Hasn’t cracked the case, though, has it?’
    ‘Maybe it helps us understand Angeles Falco a little better, and that in turn might help us to see the guy who’s watching her?’
    ‘Let’s hope so,’ said Sam. ‘All this philosophy is going on her bill.’
    ‘You have to take the opposites into account, as well,’ said JD.
    ‘Darkness and silence?’
    ‘The dark impedes light. It stops you seeing things that are there. The wardrobe, the psycho in the doorway. But silence doesn’t actually impede anything. It is silence in itself. It denotes the absence of sound. Emptiness.’
    ‘People go mad with sound,’ Sam said. ‘They hear voices. Go insane.’
    ‘Maybe that’s the guy we’re looking for?’ said JD. ‘Someone with voices in his head?’
     
    ‘Something else,’ said JD, ‘which you’ll say is completely irrelevant. If this was a novel or a Brad Pitt movie, there’d be a scene where the good guys get together and hatch a plot to make the villain show himself.’
    ‘Like using the heroine as bait?’ said Sam.
    ‘Could be, yeah. That’d give it some tension. The one who was in love with her would argue against it at first. “You can’t send that defenceless creature out into the dark night.” But eventually the other guy’d win him round. They’d take care of every eventuality they could think of, then send her out there. And she’d want to go. She’d be sure that they’d look after her.’
    ‘If this is a roundabout way of saying you want Angeles back in her own house...’
    ‘It’s not,’ said JD. ‘I’m just playing around with concepts here.’
    ‘... I’m not gonna fall for it. She’s staying in my house, and out of the way until we find some way of nailing the guy.’
    ‘What I was coming round to,’ JD continued patiently, ‘was the Heisenberg Principle.’
    Sam shook his head. ‘JD, with you on the case it never gets dull. But it never gets brought to a conclusion, either.’ He threw his hands up. ‘OK, Heisenberg, German Jew, I suppose? Nineteenth century?’
    ‘No, later than that, I think. And I don’t know squat about his origins. But I remember the principle: when you measure a system you disrupt it. So those guys who did the experiments with rats, they discovered that rats often fulfil the aspirations of the watcher. If you believe a rat in a cage will take a certain path to its food, there will be a tendency for the majority of rats to take that route.’
    ‘I’m getting a headache.’
    ‘Private eyes don’t get headaches. They get their hands smashed and they