'Do you often take these, ah, sabbaticals as a sort of busman's holiday, Ms Telman?' asked his deputy.

'This is my first sabbatical, Mr Henderson,' I told him.  'I haven't had time to establish a pattern.' Henderson was about my height, stockier.  I started walking towards one of the parts of the clean environment we hadn't visited yet; the two men jockeyed for position between the workbenches and the humming machines; a robot delivery unit on a collision course sensed us approaching and glided to a stop until we passed by.

'I think if I had a year off I'd find somewhere better than Motherwell to spend it.' He laughed, and he and Rix exchanged glances.

'It is a sabbatical, Mr Henderson, not a holiday.'

'Oh, of course.  Of course.'

'However, I did spend a month on a yacht in the Caribbean at the start of the year, without my phone or a lap-top; that got me nicely wound down,' I told them, smiling broadly behind the mask. 'Since then I've been taking the occasional little holiday to let me think, and I've travelled round a lot of the company sites I'd wanted to see but never got round to.  Plus I have spent quite a while in the Library of Congress and the British Library.'

'Ah,' Mr Henderson said. 'It's just that I thought you must have seen the inside of a chip plant before, that's all.'

'One or two,' I agreed.  Mr Henderson was right to be surprised.  In fact he was right to be suspicious, if that was what he was: despite the impression I'd been careful to give, this was not at all a casual visit.  I stopped outside a swipe-card protected door in a tall blank wall and nodded. 'Where does this go?' I asked.

'Ah, this is an area where we've got the workmen in at the moment,' Mr Rix said, waving at the door. 'Installing a new finishing line.  Can't actually go through right at this moment in time.  Too much dust and that sort of thing, you know.'