When Chloe and Dan arrived at the Matthews house that lunchtime, Leighton wasn’t there. His wife had looked out from the bedroom window at the sound of the doorbell, and knowing she’d been spotted clearly realised she had little choice but to open the door and let them in.

‘Why hasn’t he been charged?’ she demanded. Her face was a mask of expertly applied make-up, but the flush of colour at her cheeks was a telltale sign of the anger that lay beneath. She stood with her hands fixed to her hips, poised for confrontation.

Chloe found the question strange. Surely Melissa should be relieved at the fact that her husband had evaded a charge the previous evening, yet the tone of her voice suggested disappointment.

‘There are still some facts we need to be clear about,’ she told the woman. ‘Where is your husband, Mrs Matthews?’

‘He’s gone for a walk,’ Melissa said, leading them through to the kitchen. ‘Said he needed to clear his head.’

‘You don’t know where he’s gone?’

‘No.’

Do you care? Chloe wondered. She studied Melissa Matthews for a moment. Despite the events of the previous few days and the allegations made against her husband, the woman was immaculately presented, from the carefully styled hair to the shop mannequin outfit of tailored trousers and layered shirt. Her smile was as stiff as the fabric. Every word she spoke seemed wooden, as though nothing that left her mouth was said with sincerity. She gave no purchase for anyone to connect to.

But none of this made her a liar, of course.

‘Day off for you today?’ Dan asked.

‘Yes,’ Melissa said, placing a hand on the kitchen worktop. ‘Though actually, I was just about to head in. Paperwork.’

‘We won’t keep you long,’ Chloe told her, wondering why she couldn’t – or wouldn’t – complete her paperwork at home. Perhaps it was just an excuse to avoid her husband for the day. ‘We were just wondering if you could go back over what happened on Wednesday night – the night of the hit-and-run.’

Melissa seemed to fight back the urge to roll her eyes. They were a perfect match, Chloe thought: Leighton with his surly impatience and Melissa with her everything-is-too-much-for-me demeanour. Some people deserved each other.

Moving from the worktop to the table, Melissa Matthews pulled out a chair and sat down. She gestured to the chairs opposite, silently inviting Chloe and Dan to join her.

‘I haven’t been honest with you,’ she said, her face betraying no regret at the fact.

Dan shot Chloe a glance. It was what they’d all hoped for, but neither of them had expected Melissa to be so forthcoming so quickly.

‘I know who that girl is, and I know what’s going on.’

It was Chloe’s turn to look to Dan. Was Melissa referring to the fact that Leah Cross was Leighton’s daughter, or was she, as they suspected, under the misapprehension that the girl had been having an affair with her husband?

‘You’ll have to elaborate, Mrs Matthews.’

‘Leah Cross,’ Melissa said, evidently unimpressed at being made to speak the girl’s name aloud. ‘I know she’s been having an affair with my husband. Old habits die hard, apparently.’

The woman’s face was set in a stern grimace. Her husband’s history of infidelity was clearly a bitter pill she had yet to swallow. Why was she still with him? Looking around the couple’s luxury kitchen and through the bi-folding doors that opened out on to a wide expanse of back garden, Chloe thought she might have an idea. Perhaps the facade of a happily married life – the magazine-worthy home, the picture-perfect offspring – was sufficient compensation for her husband’s myriad misdemeanours. Perhaps she was prepared to overlook his infidelities for the sake of maintaining appearances. Either that, or she loved him too much to let him go.

‘Where were you on Wednesday night, Mrs Matthews?’ Chloe asked.

Melissa met her eye. ‘I was here. In bed, like I told you.’

‘And your husband?’

Melissa looked from Chloe to Dan and back again. ‘He was out,’ she said. ‘He was out all evening … he came in at around twelve thirty.’

‘Why did you lie to us? You previously claimed he was in bed with you at that time.’

Melissa sighed. ‘I thought I was protecting him. Then I wondered what for. I’ve been protecting him for years – listening to his excuses, putting up with his lies. I’m not doing it any more.’

Chloe studied the woman’s face as she spoke. Her anger was visible, snagging at the sharp edges of her tensed jaw; flitting behind the intensity of her dark eyes. Was she telling the truth, or was Alex right? Was Melissa Matthews letting her husband take the blame for her revenge?

‘When he got back, did Leighton tell you what he’d done?’ Chloe asked.

Melissa shook her head. ‘He never confesses to his sins. It takes someone to force them out of him. Now,’ she said, standing. ‘Are we done here?’