Like I said, they used to call the area the Potteries and Piggeries, I thought about this and wondered whether Ten-Tons’ ancestors had made the conscious decision to move their pigs underground. Or had their sties slowly sunk beneath the ground like a Thunderbird arriving back at Tracy Island? The latter, I decided when Ten-Tons led me by the hand through a series of domed chambers, dimly lit by carriage lamps, each with its wallow, its trough and its fat albino pigs. The troughs were full of the kind of random greenery we’d watched Kevin Nolan delivering two days ago. Unsurprisingly, I was expected to put my hands on the bloody things. Ten-Tons practically shoved me at a vast sow, who was wallowing chin-deep in mud. Despite my mum being from a small village in the middle of a forest I’m not a country person. I don’t like my bacon sandwich to be curiously snuffling at my fingers. But sometimes being police means holding your breath and fondling a pig.

The animal flesh under my hand was rough, warm and disturbingly like human skin. I gave an experimental scratch and the sow made an encouraging grunting noise.

‘Good pigs,’ I whispered to Ten-Tons. ‘Very porky.’ I swear I don’t know where this stuff comes from sometimes.

Did E. coli travel through the food chain, I wondered – I was going to have to find out. I had to find a way of getting a health inspector down here who a) wouldn’t freak out; b) wouldn’t run screaming to the media or, worse, Thames Water.

It stank here. But in an enclosed underground chamber I reckoned the smell should have killed us. In the gloom I could make out the pale shapes of men, stripped to the waist, shovelling manure into wheelbarrows – which explained where the smell was going. I remembered chatting up a good-looking Greenpeace activist during a protest in Trafalgar Square and she’d told me, in more detail than I would have liked, that pig slurry was essentially useless as manure. More like toxic waste from a factory, she’d said. And the Quiet People couldn’t have been dumping it in the Thames because Mama Thames would have come round and had a ‘conversation’ about same.

‘What do you do with the pig shit?’ I asked.

Ten-Tons squeezed my forearm in what I was beginning to recognise as his way of expressing approval and drew me down a corridor lined with shiny white tiles. ‘Cleans up nice and easily,’ whispered Ten-Tons when I stopped to feel the slick surface.