He needed a plan. Something that would cause Cassian Pewe to shoot himself in the foot.

And at this moment he didn’t have one.

He could have murdered a Starbucks latte. Or any freshly ground coffee. But he didn’t dare leave his observation post. There was only one way out of her building, regardless of whether she used the lift or the fire escape staircase, and that was through the front door he was staring at. He wasn’t taking any chances. She had remained inside for too long, much longer than normal, and he had a feeling she was up to something.

Finding her had been hard enough – and expensive enough. With just one piece of luck on his side: an old friend in the right place.

Well, actually the wrong place, because Donny Winters was in jail for identify theft and fraud, but it was Ford Open Prison, where visiting hours were reasonable and it was under an hour’s drive from here. It had been a risk going to see him, and it had cost him, for the bungs Donny said he would need.

He’d been right, of course, in his hunch. All women called their mums. And Abby’s mum was sick. Abby thought she would be safe, calling from a pay-as-you-go mobile with the number withheld. Stupid cow.

Stupid, greedy cow.

He smiled at the GSM 3060 Intercept, which sat on a wooden vegetable box in front of him now. If you were in range of either the mobile handset making the call or the mobile receiving it, you could listen in and, very usefully, see the number of the caller, even if it was withheld, and the recipient, regardless of whether it was a mobile or landline. But of course she wouldn’t know that.

He’d simply camped out in a rental car close to her mother’s flat in Eastbourne and waited for Abby to call. He hadn’t had to wait long. Then it had taken Donny just one call, to a bent mate who worked on an installation team rigging mobile phone radio masts. Within two days he had established the location of the mast which had picked up the signals from Abby’s phone.

He learned that mobile phone masts in densely populated cities were rarely more than a few hundred yards apart, and often even closer together than that. And he learned from Donny that, in addition to receiving and transmitting calls, mobile phone masts act as beacons. Even on stand-by, a phone keeps in touch with its nearest beacon, constantly transmitting a greeting signal and receiving one back.

The pattern of signals from Abby’s phone showed she barely went out of range of one particular beacon, a Vodaphone macrocell sited at the junction of Eastern Road and Boundary Road in Kemp Town.

This was a short distance from Marine Parade, which ran from the Palace Pier to the Marina, fronted on one side by some of the finest Regency fac¸ades in the city and on the other by a railed promenade and views out across the beach and the English Channel. There was a rabbit warren of streets immediately off and behind Marine Parade, most of them residential, almost all of them containing a mix of flats, cheap hotels and B &Bs.

He remembered how much she loved the sea view from his own flat and he figured she would be close to the sea now. And almost certainly have some kind of a view of it. Which had made it a simple measuring job to identify the group of streets in which she must be residing. All he’d had to do was patrol around them, disguised, in the hope that she would appear. And that had happened within three days. He had spotted her going into a newsagent on Eastern Road, then followed her back to her front door.

It had been tempting to grab her then and there, but too risky. There were people around. All she had to do was shout, and game over. That was the problem. That was the advantage she had over him. And she knew it.

The rain was coming down even harder now, drumming noisily, reverberating all around him. On a day like this it would have been nice to have room service, he thought. But hey, you couldn’t have everything! Not, at any rate, without a little patience.

He used to go fishing with his dad when he was a kid. Like him, his dad had always been into gizmos. He’d bought one of the earliest electronic floats. The first strike from a fish, pulling the float under, would trigger a short, high-pitched beep from the little transmitter on the ground beside their folding chairs.

It was similar to the beep he heard now from his interceptor system, as he flipped through the pages of the Daily Mail, a distinct, sharp, high-pitched beep. Followed by another.

The bitch was making a phone call.

The automated voice said, ‘Thank you for calling Global Express. Please press any key to continue. Thank you. To check the status of a delivery, please press 1. To request a collection, press 2. If you are an account customer requesting a collection, press 3. If you are a new customer requesting a collection, press 4. For all other enquiries, press 5.’

Abby pressed 4.

‘For deliveries within the UK, please press 1. For overseas deliveries, press 2.’

She pressed 1.

There was a brief silence. She hated these automated systems. Then she heard a couple of clicks, followed by a young, male voice.

‘Global Express. Jonathan speaking. How can I help you?’

Jonathan sounded like he’d be better suited helping young men into trousers in a gents’ outfitters.

‘Hi, Jonathan,’ she said. ‘I have a package I need delivered.’

‘No problem at all. Would that be letter size? Parcel size? Larger than that?’

‘An A4 envelope about an inch thick,’ she said.

‘No problem at all,’ Jonathan assured her. ‘And where would that be going?’

‘To an address just outside Brighton,’ she said.

‘No problem at all. And where would we be picking up from?’

‘From Brighton,’ Abby said. ‘Well, Kemp Town, actually.’

‘No problem at all.’

‘How soon can you collect?’ she asked.

‘In your area – one moment – we will collect between 4 and 7.’

‘Not before?’

‘No problem at all, but that would be an extra charge.’

She thought quickly. If the weather remained like this it would be fairly dark by about 5 o’clock. Would that be an advantage or a disadvantage?

‘Will you be sending a bike or a van?’ she asked.

‘For overnight it will be a van,’ Jonathan replied.

A revised plan was forming in her mind. ‘Is it possible you could ask them not to come before 5.30?’

‘Not to come before 5.30? Let me just check.’

There were some moments of silence. She was trying hard to think this through. So many variables. Then there was a click and Jonathan was back with her.

‘No problem at all.’