In the silence Moist thought he heard a curious sizzle, like the sound made by Iron Girder when she was relaxing after a heavy day on the straight and curves. You could perhaps call it a kind of metal purring, but it had now gone, leaving doubts that it had ever been there.

Harry looked Moist up and down and said gravely, ‘They said you flew under the train, holding two little kiddies in your arms. Did you?’

‘You know, I have absolutely no idea. I did see the kids with their heads on the tracks, listening to the funny noises on the rails, and I distinctly remember myself saying Oh bugger! Then something whacked me on the side of the head and I don’t remember a thing until I woke up in the Lady Sybil, on a bed, and that’s the truth. I am a liar for the purposes of amusement, publicity, trivial one-upmanship, personal profit and the gaiety of nations, but I’m not lying to you now.’

There was silence, broken when Harry said hoarsely, ‘You know I’m a granddad, don’t you? A little boy and a little girl, courtesy of my eldest, and I don’t often shiver, my friend, but I’m shivering now.’ Harry stood up, with eyes running tears, and said, ‘You’re the man for this, Mister Lipwig, so you tell me what I should do, please.’

Moist hadn’t expected this, but he managed to catch the metaphorical ball. ‘Clean up your act, Harry,’ he said. ‘Engineers and suchlike know all about hot steel, high speeds and wheels spinning fast, right! For most people, exhilarating speed is a runaway horse. Many people get hurt in this city every year when dear old Dobbin the dray horse suddenly feels his oats and heads for pastures new down the middle of the road.

‘My advice is to shut down the Iron Girder rides for a week, for “maintenance”. Tidy up, keep all the sharp stuff out of the way, stick up some barriers and have a few lads wandering around in uniform looking like they mean business. You know the kind of thing. Make a show of being safe.’

And now Moist heard the little sizzle again, and it seemed to sizzle in his soul, filling him with ideas, and in the theatre of his head he sat up in the gods, watching the stage of his imagination, agog to see what he came up with next.

‘It’s not just around the compound that there could be incidents like this, Harry – we need to keep an eye on the whole line. Someone to spot if there are kids on the track, or cows, or a train going the wrong way.’ He saw Harry blanch at the thought of all the things that could go wrong, but he was in full flow now. ‘They’ll need a good view – some kind of watchtower would do the trick, with a clacks attached to signal to the drivers … Ask Dick – that brain of his is coming up with new designs faster than his hand can get them down on paper.