Silence, not even the hiss of static through the speaker. Porter and Styles stood motionless, staring at the intercom, willing her to respond. Every second of silence that slipped past could be a second on the phone to her husband. Finally, after moments that felt like eons, a noise made them both look up sharply. The front door opened, and Mary Locke came out. She locked the door behind her and looked furtively both ways to neighbouring houses. She looked directly at them, but walked to the Range Rover parked off centre and got in without a word. The reflection of the sun off her window as she closed the door dazzled Porter and he shielded his face with a forearm, hearing and feeling the rumble of the gate opening as he rubbed at his eyes.

They had called her bluff and lost. Whether she had already called Locke, or would call him when she was safely away from them, it didn’t matter. The first domino had fallen and the rest would soon follow. Her engine revved as she crept out of the gate. The stars had cleared from his vision now. He saw the sun glint off her Jackie-Onassis-size sunglasses as she pulled onto the road and drew level with them.

When she stopped abruptly it took him by surprise. The driver’s side window purred as it lowered. She spoke without turning her head, eyes staring along the road in front, or at least he assumed they were; it was impossible to tell behind her dark glasses.

‘There’s a coffee shop about five miles from here called Hutton’s, near Harrow. Do you know it?’

He nodded, then realised she wouldn’t see the gesture. ‘Yes.’ He cleared his throat. ‘I know where it is.’

‘Meet me there in an hour.’

The window whirred back up and she accelerated away. Styles turned to Porter and cocked his head to the side.

‘What just happened? I thought she was going to do a vanishing act there.’

‘That’s what we detectives call catching a break, son. I knew it. I knew she was holding out on us.’

‘Holding out what, though? That’s the question.’

‘I haven’t got a bloody clue.’ Porter laughed. ‘Let’s go and find out.’

She was ready to talk, reluctant but ready. Porter didn’t understand the need to wait an hour and wondered what could be so pressing, so they opted to follow her in the absence of anything more productive. There was also a tiny part of him that thought she might make a beeline for her husband, and he wanted to be in position to head her off if that looked likely.