Wendy Aspden reached for her phone. She had Willoughby-Brown’s number on speed-dial and spoke to him through her headset. ‘We’ve got movement,’ she said, as soon as he had answered. She was looking at the screen in front of her, showing a thermal image of the front of the house. All three figures had gathered at the left-hand side of the hallway. ‘They’re heading towards the garage,’ she said. ‘Looks like they’re on the move.’

‘What about the gun case?’ asked Willoughby-Brown.

‘One went up into the attic and brought something down with him. I’m going to get things moving here and I’ll call you back.’

‘I’ll be linked in to your radio feed,’ said Willoughby-Brown.

‘You want to be in at the kill?’ asked Aspden, surprised.

‘Try to keep me away,’ said Willoughby-Brown.

Aspden ended the call, opened the door and shouted across the hallway to the SFOs: ‘Let’s get ready to move, guys. They’re heading out.’

Elyas Assadi placed the gun case in the boot of the Prius and got into the front passenger seat next to Johnny Malik, who already had the engine running. Amma al-Kawthari pulled up the garage door and Malik drove slowly out. Al-Kawthari closed the door and got into the back of the car.

The traffic was heavy and Malik had to wait several minutes before it was safe to edge out. He was breathing slowly, trying to stay calm. He checked his rear-view mirror, then accelerated to keep pace with the traffic. His mouth had gone dry and he wished he’d thought of bringing a bottle of water.

‘Are you all right, brother?’ asked Assadi.

Malik tried to smile. ‘I’m fine.’

Assadi reached over and squeezed Malik’s knee. ‘You’re doing well.’

‘I’m just nervous, brother. I don’t want anything to go wrong.’

‘Nothing will go wrong, brother,’ said al-Kawthari, from the back seat. ‘Inshallah.’

‘Everything has been planned,’ said Assadi, giving Malik’s knee another gentle squeeze. ‘Do not worry. Just follow your instructions and everything will be fine.’

Willoughby-Brown climbed into the back of the van and the driver closed the door electronically. Willoughby-Brown placed his transceiver on the table, pressed a button on a console and a screen folded down from the roof. There was a keyboard on a shelf behind the driver and he leaned forward, grabbed it and laid it on the table next to the transceiver. He put on the transceiver’s earpiece and tapped on the keyboard. The screen flickered into life. The van had mobile Wi-Fi and within seconds he had the feed from Aspden’s screen in front of him. There was a map of London and small red circles showing the locations of vehicles she had put in place.

Willoughby-Brown pressed a button to talk to the driver. ‘Can you hear me, Tim?’

‘Loud and clear, sir.’

‘Excellent. Head west, north of the river, as soon as possible. No great rush at the moment. Nice and steady.’

‘Yes, sir.’