Dead Tomorrow

62

Glenn Branson, feeling alert and wired despite his ragged night, stood in the corridor outside the briefing room, holding a cup of coffee in one hand and an All-Day Breakfast egg, bacon and sausage sandwich in the other. Members of the team were filing in through the doorway for the Wednesday morning briefing meeting.

Bella Moy stepped past him, giving him a wry smile. ‘Good morning, Mr Healthy Eating!’ she said.

Glenn mumbled a reply through a mouthful of his sandwich.

Then Bella’s phone rang. She glanced at the display before stepping to one side to answer it.

Moments later, the man Glenn was waiting for, Ray Packham, from the High-Tech Crime Unit, appeared.

‘Ray! How are you doing?’

‘I’m tired,’ he said. ‘The wife had a bad night.’

‘I’m sorry.’

‘Jen’s diabetic,’ he said, nodding. ‘We went out for a Chinese. Her blood sugar was off the scale this morning.’

‘Diabetes is a bummer.’

‘That’s the problem with Chinese restaurants – you don’t know what they put in their food. All tickety-boo in your neck of the woods?’

‘My wife’s got a medical condition too.’

‘Oh blimey, I’m sorry to hear that.’

‘Yeah, she’s developed an allergy to me.’

Packham’s eyes gleamed behind the thick lenses of his spectacles. He raised a finger. ‘Ah! I know just the chap! I’ll give you his number. Top allergist in the country!’

Glenn smiled. ‘If you’d said he was the top divorce lawyer, I might be interested. Look, before we get into the briefing, I need to ask you a quick technical question.’

‘Fire away. Divorce. Sorry to hear that.’

‘Not if you’d met my wife, you wouldn’t be. But hey! I need to pick your brains about mobile phones. Yeah?’

More people squeezed past them. Guy Batchelor greeted Glenn with a cheery, ‘Good morning.’ The DS waved his sandwich at him by way of a reply.

‘You’re a film buff, Glenn, aren’t you?’ Packham asked. ‘Did you ever see Phone Booth?’

‘Colin Farrell and Keifer Sutherland. Yeah. What about it?’

‘Crap ending, didn’t you think?’

‘It was all right.’

Ray Packham nodded. In addition to being one of the most respected computer crime experts in the force, he was the only other film buff Glenn knew.

‘I need some help on mobile phone masts, Ray. Is that your terrain?’

‘Masts? Base station masts? I’m your man! I actually do know quite a bit about them. What exactly are you after?’

‘A guy who disappeared – on a boat. He always had his phone with him. Last time he was seen was on Friday night, sailing out of Shoreham Harbour. The way I figure it is that I might be able to plot the direction he was heading in from his mobile phone signals. Through some kind of triangulation. I know it’s possible on land – what about out at sea?’

More people filed past them.

‘Well, it would depend on how far out and what kind of boat.’

‘What kind of boat?’

Packham launched into an explanation, his whole body becoming animated. It seemed that nothing in the world pleased him more than to find a home for some of the vast repository of knowledge that was stored in his head.

‘Yes. Ten miles and more, out at sea, and you can still be in range, but it depends on the structure of the boat, and where the phone is situated. You see, inside a steel tub, the range would be drastically reduced. Was this particular phone on deck, or at least in a cabin with windows? Also the height of the masts would be a big factor.’

Glenn thought hard back to his time on board the Scoob-Eee. There was a small cabin at the front that you accessed via steps, where the toilet, kitchenette and seating area were. When he had been down there, he had the impression it was mostly below the waterline. But if Jim Towers had been driving the boat, he would have been up on deck, in the partially covered wheel-house area. And if he was heading out to sea, there would have been a direct line-of-sight behind him to the shore. He explained this to Packham.

‘Super!’ he said. ‘Do you know if he made any calls?’

‘He didn’t bell his wife. I don’t know if he called anyone else.’

‘You’d need to get access to the mobile phone records. On a major crime investigation, that shouldn’t be a problem. I take it this is connected to Operation Neptune?’

‘It’s one of my lines of enquiry.’

‘So here’s the thing. If on standby, a mobile phone registers with its network every twenty minutes or so – it sort of checks in, saying, Here I am, chaps! If you’ve ever left your phone lying near your car radio you can sometimes hear that beeditty-beeditty-beep noise as interference with the radio, yes?’

Branson nodded.

‘That’s when it’s radioing in!’ Packham beamed, as if the sound was a trick he had taught all phones to perform. ‘Now, from the records, you could work out where the last registration occurred, to within a few hundred yards.’

He glanced around, conscious that almost everyone had now gone into the briefing room.

‘It would probably be in contact with, say, two or three coastal base stations and would be talking to a known sector, about a third of the circle on each.’

He glanced around again.

‘Very quickly, there is a thing called timing advance. Without getting too technical, the signal travels to and from the base station at the speed of light – three hundred thousand kilometres per second. That timing advance – depending on which network we are talking about – allows you to calculate a distance to the phone from each base station. Are you still with me?’

Glenn nodded.

‘Thus you have some approximate bearings – but, more importantly, distances from each, which together should allow you to triangulate a location within a few hundred yards. But you have to remember, this is only the place where the last registration took place. The boat could have moved twenty minutes on.’

‘So at least I would get its last known position and roughly the course it was steering?’

‘Spot on!’

‘You’re a star, Ray!’ Glenn said, writing down notes on his pad. ‘You’re a fucking star!’