I dared to see a glimmer of hope. ‘Do you have it?’ There was another pause, and I wondered if he was having second thoughts about becoming involved – with his family’s history of supporting the Royal Family, he could easily end up without a job or home if he made it into NatSec’s files. ‘Oh, Charles, I promise you I’ll make sure that nothing bad will come of it. In fact, if Nick gets out and the case is closed, it really makes us all safer. They won’t be breathing down our necks.’ There was a hiss on the line.

‘Wait.’ It went quiet for a minute, broken by the sound of movement in the background, as if things were being shifted around. Time ticked away. And finally there was a clunking sound as he lifted the receiver from his desk. ‘Richard Larren’s address is Willoughby Hospital, Willoughby, Kent. There are no more details.’

‘Oh, thank you, Charles, that’s wonderful,’ I said. ‘Thank you. I have to go now, but I’ll see you soon.’

‘Goodbye.’

I hung up. ‘Shall we call him?’ I asked Tibbot.

‘Better to turn up in person. If he knows something, he’s more likely to tell us face to face. Otherwise, he can just put the phone down.’

‘Yes, you’re right.’ I was lucky he was there, or I would have blundered my way into dead ends.

‘Let’s try that other number, though.’ We tried the number from the book again, but it wasn’t answered. Still, Richard Larren’s address held out a prospect of success. Tibbot checked a train timetable he had picked up when we arrived. ‘Willoughby’s just two stops back up towards London,’ he said. ‘We’ve got twenty minutes before the next one. Willoughby Hospital. Wonder what exactly he does there.’

We set off along the road, which had become gloomy in the twilight. As we walked, I pondered what we would find – something that exonerated Nick? Or something that proved him guilty of a plan I didn’t yet understand?

I was distracted from those thoughts, however, by a commotion – children running, adults hurrying, all in the same direction. I looked to Tibbot. ‘Nothing to do with us,’ he said.

‘But what if it is?’ There was such urgency that I thought somehow it might be connected to our search for Rachel. ‘It’s possible. We should see.’

He glanced in the direction of the station, then back at the clutch of running people. ‘All right,’ he relented.