She took a deep breath and leaned back against the linen fold panels. It was like holding four aces – the trouble being that she didn’t have a clue how to play them. If she was the nice well-brought-up girl that her mother hoped she was, she would creep away downstairs and pedal home and never mention it again. If she was a conniving bitch who desperately wanted to lever both Diana and Peter Knightley into complying with her wishes, she’d pick up the camera which was always in the cupboard along the landing with field glasses and spare mackintoshes, and happily blackmail the pair of them. But Maddy was neither of these things.

She smiled and opened the door again. Peter was still thrusting. Diana had given up the pretence and had her eyes open.

‘Get out!’ Diana sat up so quickly that Peter almost slid from the desk. ‘Get out!’

She turned wild eyed to Peter, and screamed, ‘I told you to lock that fucking door!’

Peter, totally confused, grabbed a sheaf of paper to cover his nakedness, and gawped at Maddy in the doorway.

‘Don’t worry about me,’ she said quietly. ‘I’ve seen it all before.’

Diana was struggling into her eau-de-nil skirt and cream shirt, stumbling as she did so. ‘Fuck off!’ she shrieked at Maddy. ‘What the fucking hell do you think you’re doing?’

‘Looking for you, actually. Gareth told me to come in.’

‘Gareth?’

‘Your husband.’ Maddy continued to smile. ‘Remember?’

‘Of course I know who bloody Gareth is. I mean, where is he? He’s supposed to be up on the gallops.’

‘He was. He isn’t now.’ Maddy wondered if she could push it any further but decided against it. ‘I’ll, er, wait downstairs, shall I?’

‘Just get out!’ Diana was trying to kick off the riding boots. ‘Go away! How dare you!’

Peter had put his trousers on inside-out and wouldn’t meet Maddy’s eyes as he staggered about the office.

She smiled. ‘So sorry to have disturbed you. It was obviously an inopportune moment. I’ll be back.’ And leaving two frantic faces behind her, she quietly closed the door.

Running downstairs, she felt violently sick. God, she’d have to go into the cloakroom and throw up. She clapped her hands over her mouth. She only hoped she’d make it.

She did. Just. She splashed icy water on her face and leaned back amongst the shelves of books and bottles, gulping for air. Peter and Diana … Oh, God.

Feeling shaky, she opened the cloakroom door. There was no sound from upstairs. She’d never be able to face either of them again.

‘Hi! Di, baby! Are you at home?’

A shadow loomed in the arch of the front door. Maddy shrank back into the cloakroom, but just a fraction too late. The shadow stepped into the hall and became reality.