The Bat(113)

Watkins looked uneasy. Lebie nodded slowly.

‘But I’m going to breathe underwater,’ Harry said.





THREE THIRTY.


No one in the conference room took any notice of the fan’s lament.

‘OK, we know who our man is,’ Harry said. ‘And we know he thinks the police don’t know. He’s probably thinking that I’m trying to falsify evidence against Evans White. But I’m afraid this is a very temporary situation. We can’t keep households without a phone for much longer, and besides it will soon start to look suspicious if the alleged fault isn’t fixed.

‘We have officers in position if he should appear at his home. Ditto the boat. But personally I’m convinced he’s much too careful to do anything stupid without being one hundred per cent sure that the coast is clear. It’s probably realistic to assume that at some point this evening he’ll know we’ve been in his flat. That gives us two options. We can sound the alarm bells, go out live on TV and hope we find him before he disappears. The counter-argument is that anyone who’s rigged up a system like the one he has is certain to have planned ahead. As soon as he sees his picture on the screen we risk him going underground. The second option is, therefore, to use the little time we have before he feels us breathing down his neck, to catch him while he is relatively unsuspecting.’

‘I vote we go for him,’ Lebie said, removing a hair from his shoulder.

‘Catch him?’ Watkins said. ‘Sydney has over four million inhabitants and we don’t have the slightest idea where he could be. We don’t even bloody know if he is in Sydney!’

‘No question about that,’ Harry said. ‘He’s definitely been in Sydney for the last one and a half hours.’

‘What? Are you saying he’s been seen?’

‘Yong.’ Harry gave the floor to the ever-smiling officer.

‘The mobile phone!’ he began. As though he had been asked to read his essay aloud to the class.

‘All mobile-phone conversations are linked via what are known as base stations, which receive and transmit signals. A phone company can see which subscriber’s signals the various base stations receive. Every one covers a radius of about ten kilometres. Where there is good coverage, i.e. in built-up areas, your phone is generally covered by two or more stations at once, a bit like with radio transmitters. That means that when you’re talking on the phone a phone company can locate your position to within ten kilometres. If the conversation can be picked up by two stations at once, that will reduce the area to the zone where the coverage of the two stations overlaps. If your signals are picked up by three stations, the zone is even smaller, and so on. Thus, mobiles phones cannot be traced to a single address like a standard phone, but we do have a pointer.

‘At this minute we’re in touch with three blokes from the phone company following Toowoomba’s signals. We can connect them to an open line here in the conference room. For the moment we’re receiving simultaneous signals from only two stations and the overlapping area covers the whole of the city, the harbour and half of Woolloomooloo. The good news is that he’s on the move.’

‘And what we need is a spot of luck,’ Harry chimed in.

‘We hope he moves into one of the small pockets covered by three base stations or more. If so, we can launch all the civilian cars we have at a moment’s warning and have a crumb of hope that we might find him.’

Watkins didn’t look convinced. ‘So he’s spoken to someone now, and he also called an hour and a half ago, and both times the signals were picked up by base stations in Sydney?’ he said. ‘And we’re dependent on him continuing to chat on the bloody phone to find him? And what if he doesn’t ring?’

‘We can ring him, can’t we?’ Lebie said.

‘Wonderful!’ Watkins said. His cheeks were very flushed. ‘Great idea! We can ring him every quarter of an hour pretending to be the speaking clock or some such bollocks! Which will tell him it might not be a smart idea to talk on the phone!’

‘He doesn’t need to do that,’ Yong said. ‘He doesn’t need to speak to anyone.’

‘How . . .?’

‘It’s enough for his phone to be switched on,’ Harry said. ‘It seems Toowoomba isn’t aware of this, but as long as a phone isn’t switched off, it automatically sends out a little beep every half an hour, to say it’s still alive. This beep is registered by the base stations in the same way as a conversation.’

‘So . . .’

‘So let’s keep the line open, brew up some coffee, sit tight and keep our fingers crossed.’