The PC, whose name was Andrea Kirkland, sat down and unlidded one of the coffees. Gillard took the other, which turned out to be a rather velvety macchiato. For five tranquil minutes they sat and ate, discussing family, friends and hobbies. He offered her the last biscuit, which she declined. Mount Browne is a land of no second chances, so Gillard popped the morsel into his mouth. The moment he’d done so, Rainy Macintosh wandered in.

‘Ah, workshy corner,’ she announced. ‘And no bickies left.’

Gillard had heard of Rainy’s good-natured insubordination, and smiled it away. ‘Any progress on the CCTV?’

‘Aye, sir. But not of the kind you would like.’

‘Did she stay on the train at Waterloo and go back towards Guildford?’

She shook her head. ‘No, we checked that first. Unless she stayed in coach seven, with the non-working CCTV. In which case she could be fucking anywhere, pardon my French, sir. So we’re being methodical. She got on at Clandon and we’re doing each station in turn on the way up to London, just in case she got off. We’ve split the work with the BTP. We’ve done Horsley, Effingham Junction, Cobham, Oxshott, Claygate. BTP’s working on the stations heading down from London.’

‘I just do not understand how she could have vanished into thin air.’

‘Personally I think she’s trying to disappear. Maybe she slipped into the toilet to change into a hoodie and jeans,’ Rainy said.

‘She’d still have had the violin with her,’ Gillard reminded her. ‘It’s her most valuable possession, apparently.’

‘Maybe it was just an empty violin case, which she stuffed her clothes in.’ Rainy shrugged her shoulders. ‘I don’t know, maybe she’s a magician. She’s got the hat, after all.’

The press conference at six o’clock and the attendant publicity brought forth dozens of fresh sightings of a young woman who was by all accounts striking as well as distinctively dressed. Gillard read through the notes on the clipboard which summarised titbits of information gained so far. While a couple of dozen witnesses had called the information line to say they had seen her get on the train, there were only five who had seen her come in to their coach from the adjacent one. These all agreed that she had taken a seat right at the back. Witnesses generally had a hazy idea of which coach they were in, but from their accounts some could be presumed to be in the carriage with the defective CCTV, number seven. They all described the woman squeezing into the corner, and leaving her violin and a small rucksack on the aisle seat next to her.

Frustratingly, there was a considerable difference of opinion over where she got off. Three said they had no idea, one suggested Effingham Junction, which was only two stops from where she got on, another said Clapham Junction, while the final one was certain she had not passed him to exit before he left at Waterloo. The discrepancy between the journey of the phone and the journey of the woman seemed if anything to be getting wider.