‘They must have stopped off in Basingstoke and started their journey again,’ said Button. She went over to a large-scale map of the country, tapped the M3 and ran her finger along it to the M25. ‘They’re probably on the M25 already,’ she said. ‘I need a live feed and I need it now, please.’

Liam was lying on the sofa watching an episode of Two and a Half Men on the television when Katra popped her head around the door. ‘Are you OK?’ she asked.

‘Fine.’

‘Homework all done?’

‘Sure,’ he replied, his eyes never leaving the screen.

‘Do you want to go and play football?’

‘With you?’

Katra grinned. ‘What, scared to play a girl?’

‘It’s not that,’ said Liam.

‘You need some exercise,’ said Katra. ‘It’s not good to lie around all day.’

Liam pulled a face.

‘OK, what about going shopping? We can go to the Maylord Centre.’

‘I don’t need to buy anything.’

‘We could get a game for your PlayStation.’

‘Nah, there’s nothing I want.’

‘What about a movie?’

Liam sat up. ‘Yeah, OK. What’s on?’

‘I don’t know. We’ll take pot luck. We’ll go to the cinema and see what they’ve got. It’s been ages since we’ve been.’

‘Cool,’ said Liam, using the remote to switch off the television.

Katra picked up the keys to the X3 and waited for Liam to get his jacket. They walked together to the BMW. ‘Why did Dad take the CRV?’ asked Liam.

‘The BMW needs a service,’ said Katra. She pressed the fob to unlock the doors.

‘What do you think of the X6?’ he asked.

‘X6? What is that?’

Liam looked at her in disbelief. ‘You don’t know about the BMW X6? It’s the coolest car.’ He opened the passenger door and climbed in.

‘I think this car is pretty cool,’ said Katra, getting into the driving seat. She put the key in the ignition. ‘Fasten your seat belt,’ she said.

One of the technicians jumped to her feet. ‘I have a live feed!’ she shouted. ‘I’ve found it!’ Everyone in the room turned to look at her. She was a Chinese girl in jeans and a baggy sweater that seemed several sizes too big for her. Her cheeks were flushed with excitement and her head was bobbing back and forth as she stared at her monitor.

‘Where?’ said Button, hurrying over to her.

‘M25 heading east, between Junctions Eleven and Ten.’

‘Patch it on to the main screen.’

The technician sat down, tapped on her keyboard and the CCTV image filled one of the monitors on the wall. The truck was moving slowly, hemmed in by traffic.

‘Thank goodness for weekend roadworks,’ said Button. ‘OK, we have to take care of this before they reach London.’

‘What do you have in mind?’ asked Shepherd.