She’d stood in her slip reading it over and over, before deciding that she would call Johnny and ask him to come home. When she’d told him about the note he’d advised her to call the police.

‘Do you know if either Toni or Janet received a threat like that?’ The concern in his voice was tangible.

‘I don’t know. There’s been nothing about it in the press,’ she admitted. ‘It’s probably a wind-up; a hoax or something.’ But even as she said it she didn’t feel so sure.

‘I’m coming back now. Lock the doors and keep your phone with you. It’s a long drive but I’ll be back this afternoon at some point.’ Not knowing what else to do, Johnny had driven up to Scotland to stay with his brother, giving Amy the space she’d said she needed. He now wished he’d gone to stay with a friend in London instead. Whether the note was a hoax or not, the fact was that two women had been murdered already and he didn’t want Amy to take any chances. ‘I’ll come as quickly as I can,’ he told her, already packing his bag. ‘I love you.’

There was an uncomfortable pause as Amy considered her response.

‘I love you, too,’ she said before hanging up, and she had meant it.

Amy kept glancing at the clock on the wall. She’d spoken to Johnny at 9am and was expecting him home at any moment. Looking forward to his arrival, and having decided she wanted to try to forgive him and make a go of their marriage, she’d put all of his belongings, which she’d boxed, back where they belonged. Seeing his shirts hanging in the wardrobe once more had made her feel good. Things were as they should be.

What she didn’t know was, at that moment, Johnny was lying in hospital with a punctured lung and a broken arm, in a critical condition, having been in a car accident on the motorway as he was speeding home to her.

He had been racing back to Cambridge, driving faster than usual, in order to reach Amy. His concern, having heard about the note, was palpable. There was a killer on the loose and two of his wife’s acquaintances were dead. Was she next? The fear encouraged him to press harder on the acceleration pedal and, when he was on the M1, not far from Nottingham, one of the front tyres had burst, sending the car into a spin. It had only taken a few seconds for his red Audi to smash into a blue Peugeot, before crashing into the barrier that separated the carriageways. The bonnet was crumpled and Johnny was unconscious in the driver’s seat; blood poured down his face, his arm at a peculiar angle, his chest pressed against the steering wheel.