Patrick had a feeling Koppler was wondering if he was going to ask for an autograph, but had decided that would be laying it on a bit too thick.

‘Anyway, this patient,’ Patrick said. ‘Her name’s Sharon Fredericks.’

Koppler pressed the off button on his iPod dock with a long finger. ‘You’ve no doubt heard of doctor-patient privilege.’

‘Yes, of course I have. I’m not asking you to reveal anything sensitive.’ Although what he really wanted to ask Koppler was whether he believed Fredericks was capable of abducting a child. ‘Have you had any contact with Sharon Fredericks recently?’

The psychiatrist picked up the paperweight and weighed it in his hand before replacing it on the stack.

‘Can we do this tomorrow?’ he asked. ‘I have tickets for the theatre and I really need to get going.’

Patrick tried his most charming smile. ‘It’s very important, Doctor.’

Koppler’s face creased with irritation. ‘I’m sorry, but whatever it is you need to know, I can’t help you.’ He looked at his watch then turned away and began shoving papers into his bag.

‘We believe she might be in danger,’ Patrick said, hoping to get a reaction. Koppler grunted.

This was frustrating. ‘Dr Koppler, do you have an address for her?’

This time the doctor audibly snorted. ‘I already told you I can’t give out confidential information.’

Patrick decided to appeal simultaneously to the doctor’s better nature and baser instincts. In his experience, most people loved the idea of being involved in some way in an investigation into a high-profile crime. Murders and child abductions were exciting – he imagined Koppler meeting his wife at the theatre and saying, ‘You’ll never guess what happened to me as I was leaving the office . . .’

‘This is confidential, sir. But I’m sure you’ve heard about the Child Catcher abductions.’

Koppler finally turned back to look at Patrick. ‘You think Sharon – Miss Fredericks – has something to do with that? Ridiculous.’

‘She does have a history of trying to abduct children.’

Koppler shook his head vehemently. ‘No. Not Sharon.’

Patrick waited a beat. ‘Sharon? Were the two of you close?’

The psychiatrist was flustered now. This was interesting.

Koppler stood up. ‘I really do need to go.’

He came around the desk, ushering Patrick towards the door. Patrick stood his ground. ‘Listen, Doctor Koppler, what makes you so sure Sharon Fredericks wouldn’t do it again?’

Koppler had gone pink and sweat patches were spreading on his shirt beneath his arms. This was very interesting.

‘Anything you can tell me about Sharon—’

Koppler swept his hands forward in a shooing motion. ‘Please, I must ask you to leave. I have to get going right now.’

‘When did you last see Sharon Fredericks?’