And then there were the people trying a little too hard to present themselves as harmless members of the public. They always stood out and Moist wondered if they knew how obvious they were to the trained eye of the suspicious scoundrel. They were worried and trying desperately not to look worried and nonchalance, real nonchalance, is very difficult to fake. If you didn’t have the knack it cried out … amateur.

One dwarf in particular had caught Moist’s eye as he passed, so he came back a short while later and took the seat opposite. As Moist sat rocking with the rhythm of the train, he sensed some discordance. Not fear, exactly, but the pulse of fear squashed down so heavily that it was almost singing, and in the privacy of Moist’s skull the tickertape of suspicion ticked away.

Moist had been clever so far, not staring and, indeed, trying to look like a person who was not trying not to stare, a professional nonchalant, but the dwarf who was under his eyes was sweating. Sooner or later something was going to break.

‘Oh, I know who you are!’ Moist said suddenly, keeping his voice low. ‘You’re one of those train spotters, aren’t you? I never forget an anorak.’

‘Oh, yes, I’m a very keen train spotter, sir,’ said the dwarf, keeping his voice level while his beard dripped sweat and his eyes screamed help.

‘Excellent. So you’d know the top speed of a Flyer, then, would you? No?’

Hardly anyone on the train had looked up as he subtly questioned the dwarf, as subtly as a sledgehammer; it had become an extraordinary^[68] rule of railway etiquette that other passengers’ conduct and conversation remained their private business, however obtrusive it might be. The dwarf had visibly jumped in his seat when Moist first engaged him, but he was still grave-faced and, yes, still sweating, so Moist carried on like a friend who wants to borrow money.

‘As I said, I never forget an anorak. Taking the long haul to Zemphis, are we?’

The dwarf nodded and said simply, ‘Yes.’

‘Did you see which engine we’ve got?’ said Moist. ‘I tell you what … I’m hearing some trunnion rattle. Can you feel it? Maybe she’s a new one just out of the yard?’

‘Er … yes … I suppose so …’ spluttered the wretched dwarf.

As he considered his next move, Moist looked around. Ah, there was another dwarf, further away, surreptitiously watching him watch the ersatz train spotter. Thinking furiously, he turned his attention back to the sweating dwarf in front of him.

‘Hang on, I’ve seen you before, haven’t I, at the gates of the compound, with your little notebook? We all have our little notebooks, buddy, and mine’s in my luggage over there and yours is the cleanest anorak I’ve ever seen. Real train spotters get covered in muck and smuts … it’s their badge of honour to have a greasy anorak. But you, mister, know nothing about trains or train spotting, do you?’