Before Carol could answer, there was the unmistakable sound of a key turning in the lock. They both swivelled round to face the front door, their faces rigid with surprise. The door swung open to reveal a trim woman in her late thirties. She pulled her key out of the lock, giving them both a smile whose warmth evaded her eyes. ‘Hi, you must be Carol,’ Frances said, pushing the door to behind her, stuffing her keys into her pocket and holding out her hand. Her eyes were scanning Carol from head to toe, taking in the short skirt with a slight raise of the eyebrows.

Carol shook it automatically.

‘Carol, this is Frances,’ Tony gabbled.

‘Why on earth are you hanging around in the hall?’ Frances asked.

‘We were going to make more coffee,’ Tony said, backing into the kitchen doorway.

‘I’m sorry to butt in,’ Frances said, steering Carol into the living room. ‘I feel so stupid about this. But I left a pile of fourth-year jotters that I was marking last night. I was in such a rush, I clean forgot them this morning. And I need to give them their essays back tomorrow.’

Yeah, right, thought Carol, watching with a cynical eye as Frances picked up a pile of school notebooks tucked away round the far side of the sofa.

‘I was just going to sneak in and fetch them. But if you were breaking for a cup of coffee, I might as well join you.’ Frances turned and fixed Carol with a sharp stare. ‘Unless I’m interrupting something?’

‘We’d just reached a natural break,’ Carol said stiffly. She knew she should say something along the lines of how pleased she was to meet Frances, but while she might have what it took to go undercover, she still didn’t feel comfortable lying in a social situation.

‘Tony?’ Frances called. ‘I’ll stop for a quick coffee, if that’s OK.’

‘Fine,’ came the reply from the kitchen. Carol was reassured to hear he sounded as enthusiastic as she felt.

‘You’re not at all how I’d imagined you,’ Frances said, chilly dismissal in her voice.

Carol felt fourteen again, snagged on the jagged edge of her maths teacher’s sarcasm. ‘Most people don’t have much idea about what cops are really like. I mean, we’ve all been to school, we know what to expect from teachers. But people tend to rely on TV for their images of police officers.’

‘I don’t watch much TV myself,’ Frances said. ‘But from the little that Tony has said about you, I was expecting someone more … mature, I suppose is the word. But look at you. You look more like one of my sixth-year students than a senior police officer.’