"That woman who died in her flat was definitely poisoned." said DS Cooper passing the autopsy report on Freya to DI Hanson.
"OK, that is now a murder inquiry." said DI Hanson.
"I suspect its the same group that been bumping-off wives, you know, the guys who own the Rolls-Royce left in Ramsgate." said DS Cooper.
"Anything to report on that ?" asked DI Hanson.
"No, no one has gone near it." said DS Cooper.
"I suspect they think we're watching it and will leave it there for a while until we get bored. I also suspect they will check for tracking devices, so how else can we track it ?" asked DI Hanson.
"UV paint." said DS Cooper, who after watching the blank expression on his boss's face, added "Ultraviolet Paint. It glows bright green when you shine ultraviolet eg 'black light' on it, like in discos".
"Go on." said DI Hanson.
"One of us walks past and discretely sprays a bit of UV paint on the roof of the Rolls-Royce. We then completely back-off and let the owners think we've lost interest. After a long while they recover the Rolls-Royce, and we track it by helicopter fitted with a powerful UV light source. We just look for a Rolls-Royce with a weird green glow on the roof." said DS Cooper.
"Why not track it by it's number plate." said DI Hanson.
"We are fairly certain they can change the registration number at will, and we also believe they can change the colour of the vehicle, so tracking them in the normal way might not work, especially if we lose sight of them. They won't be able to get round this." said DS Cooper feeling pretty pleased with himself.
"We will need to brief all the various agencies what to look for." said DI Hanson.
"Ah I've just had a thought. To make it easier to see in daylight, we pulse the UV light on and off so the chopper pilots just have to search for a black Rolls-Royce with a flashing green blob on the roof." added DS Cooper.
"OK, good idea." said DI Hanson.
"And once we know that the owners have recovered the Rolls, we can link it's location with any mobile phones inside." said DS Cooper.
"How do we know where the phones are ?" asked DI Hanson wishing he had paid a bit more attention to 'all that computer shit' !
"There are two methods. The mobile network has to know roughly where each phone is so it can route it's voice and text data to the nearest cell tower. They can normally locate a phone to within a few hundred yards, and if other cell towers are in range, within a few tens of yards by signal-strength triangulation." said DS Cooper.
"And the second ?" asked DI Hanson.
"Nearly all modern phones have GPS built-in and that location data can be accessed via various back-doors built into those phones, but we would need either the number, IMEI or IMSI". said DS Cooper.
"IME what !" asked DI Hanson.
"IMEI - International Mobile Equipment Identity. It's a unique number assigned to every mobile device." explained DS Cooper.
"And the other one ?" asked DI Hanson.
"IMSI - International Mobile Subscriber Indicator. It's a unique number assigned to every mobile user." explained DS Cooper.
"OK. How do we access the location data ?" asked DI Hanson.
"The cell tower data can also be accessed from the mobile networks. Most have some kind of portal that we can use. We can also download the data to analyse on our systems." said DS Cooper. "The NSA and GCHQ have a direct 'pipe' into the mobile networks, it's a real pity we can't get into that." continued DS Cooper.
"Don't we have to wait 30 seconds ... like in the movies ?" said DI Hanson.
"No, that's Hollywood bullshit to add suspense to a movie. The location data is real-time." said DS Cooper wondering where his boss got his technical knowledge from.
"And once we have that, we can associate their phones with the phones of anybody they meet up with ?" asked DI Hanson.
"Yes. Either by their location or by the fact that they texted or called them. After a while we will get a detailed profile of who they communicate with." confirmed DS Cooper.
"How will we know when the Rolls has been recovered, we can't keep a chopper in the air long periods." asked DI Hanson.
"We can park a car nearby with a motion-sensitive camera on board. When the Rolls moves we get a text alert." said DS Cooper.
"OK troops, lets do it. These guys have been annoying me for ages, I will be very glad to put them behind bars." said DI Hanson.
Many miles away the two men are on board the Drettmann yacht on their way to Cows on the Isle of Wight.
"Is our new vehicle ready ?" asked the first man.
"Yes. It's black SUV with all the latest toys." said the second man.
"I do miss the Rolls." said the first man.
"We have been watching it for some time and no one has paid any attention to it so far." said the second man.
"OK. I think we should try to recover it in a while." said the first man.
"Agreed but there is a serious risk if we try to get it too early." said the second man.
"I know, but we have been very careful, so we should be OK." said the first man.
"OK. I'll get one of the guys on it." said the second man.
Back in Ramsgate a plain clothes policeman walks towards the Rolls-Royce with a large syringe filled with special UV paint. As he walks past he pushes the plunger and spays the roof. He continues to walk through the car park and then outside.
The two men on the yacht reach their destination. While the crew starts the mooring process the two men consider their next moves.
"Who's going to get the Rolls-Royce ?" asked the first man.
"I'll get Unit 5 on the case. I'll brief them about the possibility that the police might be tracking it." said the second man.
"Hey boss, we have movement on the Rolls-Royce." said a very excited DS Cooper.
"At last ! I was beginning to think they didn't want it back. Get that specially adapted chopper in the air." said DI Hanson.
Keith drove the Rolls-Royce totally expecting the police to be following behind somewhere and would take the normal precautions like going under a tunnel and change colour a few times. What he couldn't have known at the time was that method wasn't going to work, the police just had to fly above with their specially prepared helicopter and look for the flashing green blob on his roof.
"OK boss, we have a sighting along the M2 heading west. I'll make a note of the locations so we can match it up with the phone location data." said DS Cooper.
"How may data points do you need ?" said DC Moss.
"Get as many as you can along the M2. We need to be sure we've got the right guys." said DS Cooper "Boss, the chopper pilot says he can't follow them for much longer, he needs to return to base shortly." he added.
"OK, when you're sure you have the owner's numbers let the chopper go. We can track them via their phones now." said DI Hanson.
"We have associated a few more mobile phones with the one in the Rolls-Royce, courtesy of GCHQ who will soon be able to give us real-time location data on all the other phones." said DS Cooper " ... including one belonging a hacker who we thought was dead !" he continued.
"Good. It's about time we wrapped this up, the boss is getting a bit impatient." said DI Hanson " ... who was the hacker ?" he asked.
"Your friend Greg Goodman, it was his burner phone we tracked to an apartment block where it suddenly stopped." said DS Cooper.
"So that's what happened to him, I didn't quite buy the official story. Perhaps we should visit that apartment." said DI Hanson.
"When we have the locations of the others. Shall I get the local units to pick them up ?" asked DS Cooper.
"No. They probably suspect we are tracking them and they probably sent someone low in the food-chain. We want the guys at the top. So we just play a waiting game, let them think we're not interested so they get careless, we keep gathering intel and when we're ready - bang !" said DI Hanson.
"Wouldn't the guys at the top be in the Rolls ?" asked DS Cooper.
"Probably, but its unlikely they're in the Rolls now." said DI Hanson.