‘She’s dead, isn’t she?’ Rainy asked quietly. ‘Otherwise she would have given them the pin code to save her life, wouldn’t she?’

Gillard bit his lip, and nodded. ‘It seems quite likely.’

‘Och, the poor wee lassie.’

Adrian Singer was arrested in London on Friday afternoon and brought to Epsom Police Station for questioning. Meanwhile, CSI crawled all over his charming cottage in Westmeare, then bagged up his computer and other devices to be analysed.

The man himself, fairly peeved to have been dragged out of a Royal College of Music brass tutorial in front of two students, sat in a baggy jacket and cargo trousers with his arms folded while Gillard and Claire Mulholland went over his account of the evening spent with Beatrice Ulbricht.

After two hours of going backwards and forwards over his story Gillard said: ‘So just to be clear, you offered her the spare bedroom, and made no move on her. I can’t understand why she suddenly became so upset that she would leave immediately, especially given how uncertain the bus services were.’

Singer gave a long sigh, and said: ‘Look. I might have given her a hint that if she wanted to come to my room, that wouldn’t be a problem. I imagine that’s why she got upset.’

‘What kind of hint?’ Claire asked.

‘Honestly, it was nothing. She could just have ignored it.’

‘Can you remember what words you used?’

‘No, not really. We’d both had a bit to drink But I do recall thinking it was absurd that she should decide to leave at that point.’

‘What time was this?’ Gillard asked.

‘At 10.45 p.m., I think.’

‘Beatrice has money. I’m wondering why she didn’t just ring a taxi,’ Claire said.

‘I told her that there weren’t any nearby, which isn’t quite true. She couldn’t get a signal on her mobile either, typical for Westmeare.’ He paused and then said, ‘I told her there was a bus at eleven o’clock which stopped at Clandon station.’

‘That was a lie, wasn’t it?’ Gillard said.

Singer nodded. ‘I was really hoping she would stay. I thought that I would leave her at the bus stop for half an hour, to cool down, and then go and fetch her and bring her back.’

Claire folded her arms. ‘I don’t think you’re a very good judge of a woman’s character, if you expected leaving her to stew at a rainswept bus stop where the promised service never arrived would improve her mood.’

Singer shrugged. ‘I feel terrible about what happened, really I do. But I didn’t have anything to do with her disappearance. I promise you that.’

‘Sadly, we’re not in the position to take your word.’ Gillard looked down at his notes. It would take a few hours more for forensics to finish with the samples taken from Singer’s home. Going through his computer would probably take days. His gut instinct was that Singer was telling the truth, more or less. He had one gambit left to take.